I'm almost positive that my most expensive meals were those paid for on business expense accounts. So I don't have any prices to quote, but we sure ate in some great places.
DR Laura mentioned the Blue Bayou at Disneyland. I'll betcha my truly most expensive meal was the one had upstairs from there, in Club 33, on someone else's private membership. I know those memberships used to cost in the thousands per year, so it's probably billions now. An incredible experience, with acres of wonderful food to die for.