Warcraft 1 & 2 had two races
WC3 had 4 races (roughly), + High-Elves (which could be played if you possessed one of the workers)
Expansion had Naga as well.
It doens't have to be balanced-some races are minor
BALANCE IS EVERYTHING!!! Biggest problem with WoW is balance. No balance causes everyone to be angry and mad.
The ones that are balanced will be the Major races and games between those ones only would be ranked, otherwise casual gameplay. And no i haven't started the game cuz im only 16 years old. im going to college for it. so in truth only like six or seven core races would have to be balanced. other would be there becuase of gameplay options and additional fun. no it shouldn't be $100 becase just make the models, program it and don't worry about balancing some of the races.
Google Base Invaders, download it, and play it. Also look at the source code. It took a team of 5 to create a game like that. If you think you can do that for 17
unique different races, good luck.