Due to its poor form of distribution, ( as i have been taught by
@savvy.max ), It is simply an over valued item. The annoying money trading for inferno also causes an awkward fluctuation for the value of it (in game versus real world) , as trading two stitch hats in game is considered under offering while selling two stitch hats and buying an inferno is over offering (not that I would recommend real world trading for in game items) So, my point is: even though 80-100 firewalls is accurate, I would try to attain it when they release it through competitions (which i'm sure they will again eventually, but who knows) rather than trading for it. Lastly, The fact that only a few people who trade it push the price of inferno up a ridiculous amount ( not that I have anything against my fellow VMKers) contributes to its poor justification of value.
Sorry, I thought this post was somewhat of an appropriate place to rant about this, and I'm bored at work)