This is Spinal Tap. The members of the heavy-metal band Spinal Tap (David St. Hubbins, Nigel Tufnel, and Derek Smalls) wax nostalgic on the DVD commentary track of the 1984 Rob Reiner film about the guitars seen in the movie, stating that many of them can now be found on eBay.
The Simpsons (episode BABF22). Homer loses his life savings in the stock market, except for a few remaining dollars he spends on a cowbell. He rings the cowbell gently, only to have it break apart in his hands, and yells "Damn you, eBay!"