I have a love/hate relationship with DP, I do use them for logo design, because I'm super picky. Ive bought about 6 logos, I haven't used any.
I bought a header too that I used on a site I sold.
The thing is if I'm as picky as I am, and I try to be as clear as I can.. I think I have better odds that SOMEONE will get my point in a contest.
Frankly though, I think if you pay more, you get more. I get a bunch of people that will together try to grasp my concept in contests, if I ever get a winner, I'd expect to pay more for someone to really put some time and effort into designing me something great. Probably more than $75 to be honest.
To design something fabulous and 100% unique takes time.. but really, you have to decide what an hour is worth to you. When you're lessor known, an hour of your time is though worth less than after you're established.
So all of my blathering here really comes back to cliches involving supply and demand.
