I think that what determines whether the number of schools you applied to is enough is which schools you're applying to. If you have a 30 and 3.5 and apply to 10 schools, that's probably more than enough assuming that no more than a few of those schools are top schools. I have a 33/3.83 and I'm applying to 15 schools: 4 top-tens, 6 highly ranked, and 5 "safety" (state, etc.)...
I don't think you guys should worry about whether you're applying to too few - just make sure that you apply to a good number of schools whose average stats match yours.
My 2 cents...
- Quid