If you want a good logo, spend that $100 on 4 different but competent designers and get them to give you a shit ton of designs. Offcourse it would be as much as 300+ entries but this is just.. almost akin to slave labor. I won't ride the high horse though. I've been on both sides of this coin.
Nothing against you, I have always stayed against this contest economy. Utterly devalues the time of a freelancer.
Btw.
If you really want some a better quality result by running contests. trying visiting 99designs.com
Lately, i thought 100$ would be the best rate for a logo, But no professional designer has applied. Actually, the design we have received till now are not upto the mark. So, I believe I should go to 99design website or increasing the price at the freelancer.
I see every individual has there own opinion, From my point of view, through contest once can get something really nice.