I'm not a graphic designer but I think you are seriously underestimating what this kind of work costs. If you want pro work, you gotta pay a pro price. People will invest time and talent for a
chance at winning .2btc, that's the kind of work you're gonna get. If .2 is the budget, then straight up hire a freelancer for a couple of hours instead of running a contest. .2 is insulting for those who actually went to school to learn the craft.