Not quite a $18K burger: I was in buckhead, a trendy area of atlanta in the early 1990s, having lunch at a fancy place there. On the menu is a "world famous burger", complimentary of a bottle of nice wine. the note next to the item said: please allow 15 minutes so our waiters can cross the street safely.
Curious about it, I asked why. The waiter pointed me towards a Wendy's on the other side of the street, saying that's where you will be getting their "world famous burger".
Total fare of like $250, pretty much entirely in the wine.