The prices are driven by the players, not Blizzard. Could blizzard do something to lower the prices via making epic gems available to buy with VP? I'm sure they could try, but I really doubt it would knock the AH price down to dramatically. The BoE valor bracers and boots still sell for around 5k give or take, people would be expecting a similar number for the epic gems they purchase with their Valor Points. As for rare gems, well, they would be sold for JP I'm guessing and again, the price would not drop as much as you would expect.

Gems, glyphs, flasks, and enchants are PURELY player driven markets. Whether you go into a non-heroic 5 man to solo mobs and farm celestial essences, run around twilight highlands grabbing ore and herbs to prospect, mill, or uhhh.. potionize.. it is all something done by a player. The only way for the market price to be lowered is for you to invest a lot of time into farming up insane amounts of the product you want to see drop in price and list it on the AH for what you believe is a reasonable price. You will need to do this daily, for months, until finally you run to the AH one day and notice your stock being the most expensive auction listed.

Now this isn't so true with epic gems as it is with every other material seeing as any player can only receive a maximum of 8 epic gems per week without buying any, and letting them become a rare prospect from pyrium would be nice, however, the argument does hold true for enchants which seems to the focus of the comment. I deck out all my 85s in BiS enchants and make a little extra cash by farming green level items at the start of each patch. I'll also camp the AH and buy any ilvl 272+ weapon that is listed at 10g or less. Is it amazingly awesome and fun to do this? No, not really, however I do have the option to pay the 1 - 2k gold per enchant should I feel its not worth my time to save the gold.