What Product Did You Overspend On?

For me it was the Musical Fidelity M6 500i, an outstanding IA. . . in the store, but in my system it was terrible sounding. I was unable to single out the reason it performed so poorly in my system, but I did get rid of it.

Those MFSL/DCC compact discs from the late 80's to early 90's.

Power cables and interconnects. I do hear a difference but do feel they cost way too much money for what you get.
Vinyl costs are also getting out of hand I think.

A pair of Usher BE-10 but the dealer, graciously, returned my money after 3 days.

One of the worst loudspeakers ever built. Rivaled the B&W 800 series for unlistenability.