Thanks, y'all! If the buyer paid $85, that's $5.32/serving, figuring 16 slices, or $7.08/serving, figuring 12 slices, which seems more reasonable since it's an 8-inch cake. The Wilton yearbook says you should be able to get 20 "party slices" (bigger than "wedding slices") from an 8-inch cake but that's just crazy talk.
This is what I wanted the cake to look like:
…but maybe something even more Wedgwoody, a little more Federalist, y'know? But I ran completely out of white icing after I put on the top border (shoulda used a smaller tip), and the colored flowers were just a panicked afterthought. But somebody liked it, and better luck next cake.