Cfrock
Keep it strong
That's a great idea. Although perhaps it may be more practical to have set denominations for a first, second and third place win rather than for a submission. Something like 1st prize = 20G; 2nd = 10G 3rd = 5G
Gold as a prize is actually a much better idea. It would still provide that incentive to enter and having a prize beyond an icon under your username would a good reward for winning.