I don't think it would be a waste of money at all. I applied to those schools and my numbers are pretty similar to yours (3.82, 35 MCAT). You are either average or a little below MCAT average for a lot of the top schools, and your gpa/ECs are stellar. Sinai's app is pretty easy (why sinai, how will you add to diversity). Cornell's is easy too (why cornell, what are you doing this year?). Harvard is basically just What have you done since graduation? I think your stats are excellent and your ECs make you unique, you have a shot at Sinai, Cornell and other top schools for sure (Harvard is of course a crapshoot for even the best).