Fans seem to like Rock-'n'-Roll racing (I've never played it). And as I'm sure you know, almost any SNES RPGs should get a rediculous price.
Yes, Rock N' Roll Racing is very, very good and addictive, it should make some profit. As for sports games, they usually sell for much less... I'm not quite too sure of the reason, but buying sports games for $10 is not "on my to do list".