I think that this would work out fantastically, though not in the way the OP intends. Here's why-

Everyone wants to be unique but no one really is. In the end, most of the unique players uniquely have a bunch of vial bandoliers and maybe some kind of cool costume but their gear, their everything, it's all the same collection of brandishes, winmillions, whatever. So what we do, is implement a new ticket item that costs one million energy or so.

When used, this absurdly rare ticket prompts the player to choose a special name, a common name, a description, one existing weapon line, any number of status effects, and a damage type. This information is then sent to the developers, who will reskin whatever item they chose, slap on the status effects, and hand it to the player, no questions asked. The item in question will then be given to the player with a special name+particle effect attached to it, and released via featured auctions for a b/o of one million crowns, rarely.

If people immediately come in and try to order a haze bomb that has all of the status effects sans ice, they're going to get back something like a haze bomb that does all of the statuses but takes 900 years to charge or randomly does one status. If people try to get a dread venom striker that does pure shadow damage, it will have a small damage reduction so that it isn't just game breaking. Doesn't matter if it's a bit on the OP side, because it's going to be a novelty item that only a small percentage of the players will ever even see and if people want to make their game incredibly easy that's their decision.

As for the pricing, one million energy is held by only a handful of players that dominate the various markets in the game, and comes out to around two thousand dollars which sounds like a good deal (for Sega Networks Incorporated) to me.