"eBay" is a song by "Weird Al" Yankovic, it is a parody of what song by the Backstreet Boys?
EBay (song):  It is a parody of "I Want It That Way" by Backstreet Boys. Backstreet Boys: The Backstreet Boys (often abbreviated as BSB) are an American vocal group, formed in Orlando, Florida in 1993.
I Want It That Way