So that's a hard question to answer. My friend gave up on the cheapest since they needed "one" so bulk pricing and shipping costs blew away many places. They settled on Amazon Prime since that worked for them.
So I've been searching the internet for an mp3 player, and as I have had excellent experiences with Sandisk in the past, I decided on the Sansa Sandisk Fuze, (not the Fuze+.) However, I'm trying to find the best price for one in good condition. Where should I look?