more likely to much much more though, expect it to be 6x the price of hc end game weapon like it is on wotlk

we don't even know what the pricing of hc end game stuff is going to be but if 27 coins for 378 gear, you can imagine 419 will be much more.

this is all just a guess though, if you go with it you wont be disappointed if it turns out to be true and if it's less then you will be happy about it.
Or they may just drop the price for the old gear. And if people didn't use third party systems to "hack" the quest Molten wouldn't need to disable it. Tragedy of the commons and whatnot. Greedy nabs can't just work for it.