As I said during the event...
The Toadstool and Gothic skins should all be in the Builders Guild.
They should be simple trades:
Normal building and 10 Black Petals for a Gothic building - 1sec trade (maybe with an autocollect feature)
Gothic building for Regular Building - 1sec trade
Normal building and 10ea mossy beams and blocks for a toadstool building - 1sec trade
Toadstool building for a regular building - 1sec trade
Storm8 please fix this!