"Has any one else considered this?"
I see no reason to expect a price crash due to class d amps. Solid state amps are "superior" to tube amps and you don't see a run on those things. Even vintage tube amps sell for high prices.
A lot of the high end companies have been selling class d amps for years now. Rowland only makes class d amps now for 10+ years. ARC, PS Audio, Theta, Cary, Rotel, NAD, Wadia, and countless others, all make class d amps.