OP said the payment would be to that address, so you can introduce other people's addresses if you find them cool and want THEM to win.
Yep, I knew that and although I wrote "a list of vanity addresses, mine
and others'" you're right: this may indeed need to be emphasized more. The owner of the vanity address will actually win that money.
for 20$
I think that the first faucets were giving out entire bitcoins at start. I mean, give it time and don't underestimate the current USD value, since we talk about Bitcoin here
Now on-topic: indeed, 20$ should not need escrow. On the other hand, OP needs a way to show commitment, since he's rather new and not known... and it's not the only missing bit from a proper contest.