Cost: 1,500,000 

In 2004, Latrell Sprewell is so incensed by a three-year, $21M contract offer that he retires from basketball and says, "I have to feed my family." Apparently unaware that income plays an essential role in the grocery shopping experience, Sprewell spends the next few years fighting multiple foreclosures and burning through nearly $100M in career earnings. After defaulting on his $1.5M yacht nicknamed, "Milwaukee's Best," it's seized by US Marshals.

We don't know why a guy who once made $14M in a single season pulled out a mortgage on a boat, but we do know it was an extremely stupid purchase.