Just want to emphasize my point on money not being a factor in your decision. Consider you could be getting paid $8500 by working for <big company x>. That's $9000 over your summer, peanuts compared to your life earnings. Don't sweat it, you'll have the awesome experience of working for a small startup (something I never did), and probably make some really good friends. Enjoy life, you're getting paid many multiples what people with college degrees are making :).