It all depends on how much you plan on selling keys for. The game's economy will rely heavily on them being expensive I think (5000+ credits each, at least). Putting them up for sale will cause rarities to go down and probably cause a ton of controversy. I think if keys go on sale, the current rares and super rares should be retired and replaced. This will avoid widespread commotion and add a lot of variety to the economy. Anything can be super rare if you make it so I don't think adding items to the game and replacing them would be a huge deal (but then again, what do I know about coding.) In essence, expensive keys + new rares or the extinction of the system would be the only viable options. You'd be creating a bigger problem than you're trying to fix otherwise.
I'm gonna add to this, because Cat got me thinking. It's not a fair system to continue due to the game's mechanics. What's a Stitch hat worth in Golden Snowmen? For this example let's say 20. Someone slaves over their computer for a month (realistically it would probably take a lot longer) earning those 600,000 credits to buy those snowmen, only to go and trade them to someone who managed to get a Stitch on their 6th key in their first day of playing (me) due to pure luck. I realize super rares are not the only valuable items in this game, but this game's economy makes them the endgame of valuable items. In essence, 95 percent of people who keep up with the economy essentially strive to become rich enough to own a super rare. Someone spending a huge amount of time and credits on earning this one item that was obtained by Jonny Foundakey on his first day is almost a slap in the face due to the game's current state. You might say that it's someone's choice to do such an exchange, which is entirely true, but in anyone's hindsight, you just wasted a months of your time and credits to wear Stitch's decapitated cranium on your head.
If this continues, the rich are only get richer, as they already are. Someone with a Stitch hat can get someone to undervalue their goods because the brain's argument is "you can have Stitch now, or go find 100 keys and take a chance". So now, after using all that time to get those credits, they have 2 grueling options: over-offer on this person's Stitch hat that took 45 minutes for them to obtain, or go waste another month looking for keys for the slim chance that you'll get a Stitch hat.
The luck system has too much control over the game. Let's look at the statistics and how people misunderstand them. It's very common to think with a 1/100 chance of finding a Stitch hat (assuming the game uses a simple RNG like everyone says), using 100 keys should yield one. Before committing to something like finding 100 keys, do yourself a favor and go to random.org and click the generate button on the right side. Assign a number to your Stitch hat (1, 48, 85, doesn't matter, you have an equal chance of rolling all of them.) Keep track of how many rolls it takes to get your Stitch hat. Some people may get it within 5 rolls, for others it may take 200-300+. Do this multiple times, because if you get it within your first 10 rolls or so, you've most likely just convinced yourself to waste your time collecting keys to have those same chances. It doesn't work like that.
Here's a simple way to change your perception on that 1/100 chance. Ignore the 100 as the amount of keys you have; it's irrelevant. Think of it simply as an RNG, just prettied up with animated keys and crates. You have a 1/100 of getting that Stitch hat with each key, that does not mean you have a 100 percent chance of getting one with 100 keys. What most people don't realize is that
that statistic applies to every key you use. Do not think of the 100 as the amount of keys it would take, you will trick yourself. You could use 1000 keys and not get a Stitch hat because that RNG didn't roll your number, and it would be completely fair, because
1/100 does not mean what you think it means. You could get Stitch on your first key and it would be completely fair. You could get all four super rares in a row, as slim a chance as that is, and it'd be completely fair because
statistics are deceiving.
So here's what I think has happened and what should happen. I don't know what the staff's intentions were/are on the game's economy, but despite all I've said, they're doing a good job of regulating it. They know it's probably the biggest reason people play the game, and recreating this economy can't be an easy job for any of them (and personally I think that the problem at hand is minuscule compared to what this game could've been in other people's hands.) Point is, the economy needed to be started somehow. The game is relatively new. It needed to include items of all different rarities to capture the essence of what everyone wanted back: the original VMK. The fact of it is is that
this system of sheer luck was/is almost a necessity, but it didn't/doesn't have to be the only method of obtaining what we all hold on a pedestal. Credits are a huge part of the game, they tie into mini games and NPC interaction, and of course you use them to buy and sell things. While there are things that have become rare after being on sale, it currently doesn't have a reliable or predictable effect on the economy (which a crate + key system with an RNG does excellently), but it can. Hard work should pay off in this game.
There are a few important things both the luck system and the work system do: they directly affect a player's lifespan. As I said before, I uncrated my Stitch hat with my 6th key on my first day of playing. I'm not saying all players are like me, but the hard truth is that I wouldn't have continued to play if I had no reason to. My intentions were to revisit VMK for a day or two for my memory's sake, but all of the sudden, I meant something to the economy of the game. I could do anything I wanted with this hat because people wanted it. I had the single most demanded item in the game (at the time at least, there were 20-something in the game.) I wasn't just going to quit with all that power. So I played more, and made friends. Two days later I gave my Stitch hat to Shrimp, because she's awesome, and now Stitch wasn't the only thing keeping me playing. The key and crate system hooked me and the Stitch hat reeled me in. Humans like taking chances and gambling; it's one of our basic human natures.
While my example of me giving away my super rare isn't great, what does this mean for someone who never got one and really wants one? They have the same chances as me so why can't they get it on their 6th key? Because statistics deceive you. We are curious, but we also learn. After 30, 40, or 50 keys, clamming and Fireworks doesn't seem so desirable anymore. Keys and crates are worthless to you. For persistent people who made it to 100+ keys, they're story is much more sad.
But, while collecting those keys, you also collected credits, right? So you can go off and buy... a Gold Snowman... with credits that took you two weeks to earn. Oh, and it's worth just a small sliver of my Stitch hat that Lady Luck gave me. So do that for a little (read: lot) longer, and MAYBE you'll find someone who wants to trade their Stitch hat for your Snowmen. That's what credits are worth to the game.
Unless we give credits a more important purpose.
Put super rares on sale. For the sake of avoiding controversy and complete outrage, retire the current ones and don't put them in the catalog. Let the lucky have their cake and eat it just this once, but change the way this stuff happens from now on. Crates are still very important to a lot of people though, so maybe I don't think we should get rid of them. People like gambling and that's fine. But maybe this time, add some Gold Ears to the game, put them in the shop for 300k (or whatever it would take to make them super rare material), slap them in crates as well, who cares. Give them 1/200 chance of being found maybe. This way, people can work for their wealth or gamble for it. This is a game after all, we shouldn't condemn people's choices or take away their ability to choose. It's a trivial factor in the grand scheme of things, as long as every player with a different preference has an equal chance at success. You could spend a month of credits on some Gold Ears, or uncrate them after collecting a month's worth of keys. Everyone who wants to work wins. If you don't want to work hard for your success, you should learn to be content with your crate chances because you have no room to complain. There will, of course, be people with great luck uncrating them on their 6th key, but that's the luck of the draw. Choose whether you want to work towards your goal with a guaranteed outcome (credits), or whether you want to try your luck at cutting the time and effort in half (uncrating). Luck applies to so many things in life and there's no reason we should take that excitement out of the game. In the event of that, we'll continue the same controversy, in contrary fashion.
This is one of those situations that can be solved in everyone's favor. Give us variety and choices, and the game and the people will flourish.
(Sorry for the huge post, they upped my ADHD medicine today :v)