Still, a decent film scanner (not a drum scanner but a good, high-quality film scanner) will set you back under $2500 and that's a lot cheaper than getting a digital back for the 645.

I toy with that idea myself: get a good medium-format camera with a very good lens and a good scanner and see whether that combination is worth the time and effort over "affordable" DSLRs. That would be simply for the "fun" photography -- you know, the stuff that doesn't make me any $$$$ .

Jim