So, I spent 33 Gold and about a million food(200,000 from the Arctic Isles) to go from 5th place to 2nd.
15 for a boost and 18 to finish breeding and evolving.
I didn't even really care about the Grand Prize Dragon as I don't think it looks good, but I saw how cheaply I could win it, so it was an easy steal. I really feel bad for the previous second placer, though. They boosted a few times throughout the competition, if I'm not mistaken. I only spent Gold just now at the very end to steal second place.