here's an idea: the first playable race is humans, and humans only. as you progress through the game, you discover new races, and if you do a major quest for that race, you unlock them as a playable character. E.G visit avian home world Ordered to enter sacred temple as a "trial of faith". go through temple, defeat a avian creature (boss or something) come out, blessing is bestowed upon you. you can now play as avians and trade/interact with their kind! (and just for the fun of it) ????? best seller/PROFIT.
Maybe if they give awesome racial abilities to a certain race they could limit use of it by making following your suggestion (for that race/those races alone) but that should not be the case for most races, almost (if not) everyone should be able to start as the race of their choosing