Another thought I've had: what about a system that allowed developers to sell multiple 'editions' of their games?
For example, Full Bore is currently available direct from the site as the standard game, or the 'soundtrack edition' that also comes with the soundtrack, but costs more money. This would allow developers to still distribute their bonus content via IndieGameStand without:
- losing money
- overcharging the people who don't want the bonuses
Another way you could do this would be to allow the developers to set a separate price on the bonuses for a game, so that if you wanted the soundtrack, you would just pay for that and
the game. This wouldn't work for games with 'special editions' though where the upgraded game is actually different than the standard game (the Megabyte Punch special edition has more multiplayer levels, for example).