Sega is experimenting with the free-to-play model right now on the 3DS in Japan, and it looks like it might yield some favorable results. They're scheduled to release their first F2P title soon with Initial D: Perfect Drift Online, and according to Famitsu, it looks like more games based on the model are in the works.
Essentially, Sega is selling a "fair" F2P model where you can earn everything by playing offline or online, but you can "speed up the process" through IAP -- in essence, the same system as Gran Turismo 6. Project head Toshihiro Nagoshi (of Yakuza fame) is hopeful for the model on 3DS, despite the fact that smartphones would result in a larger customer base.
It'll be really interesting to see how crowds react to the pricing scheme on the 3DS. As long as they don't go overboard, it could be a cool option. I'm not completely sure that I trust Sega to handle it with tact, though.