Aliasalpha: The problem is that they'd need permission for emulating the hardware as well as running the software which would mean either they'd have to add a licencing fee to each game to cover the cost of the bundled emulator or they'd have to sell the emulator seperately and sell the games without the emulator.
Also, no matter how much I loved both systems, there's no way in hell I'd be paying 6-10 bucks for a single C64/amiga game (and no chance of buying bundles of 5 or 10 to get the 1 game I want, thats the reason I dumped pay tv), they'd definitely need a much lower price point. I'd happily pay a dollar or MAYBE 2 for a C64 or Amiga game if it was a really good one
There were c64 games that had every bit as much gameplay as most current GOG titles: The Legend of Blacksilver, Temple of Apshia (might have that one spelled wrong), Wasteland, all the Bard's Tales, etc. I'd have no problem paying 5.99 for any of the above.