The price of the cards I use for GPU mining initially cost me $270 per.  Comparable cards cannot be found on newegg.com, and the "out of stock" price listed is >$500 per card.  AMD and NVIDA cards are just not competing.  My bet is that ATI knows exactly why their cards are selling so well and would be willing to create low cost ASIC, FPGA, or GPU hardware specifically targeted to mining.  If I were NVIDA or AMD, I would be searching for ways to cater to this market as well.  

If you are really concerned about a threat to FPGA centralization of computing power, start an email campaign to NVIDA and AMD asking them to create hardware specific cards to meet our mining needs.  All that is needed is a bit more competition.

EDIT: Cleaned up awkward wording.