If you're talking about design inspired MP4 players, then yes DHGate is the first place to find them. Basically all of their merchandise is this way. They could seem really good too, the actual MP4 players.
But they're not much quality. If you wish to take the jump on it though sellerkey.com has what you're asking about. $50 MP4 players are definitely selling at that rate for a reason.
If they were first class they would be in the $100 range, that said they do make an excellent deal break and do sell out quickly. Probably the best route to go is buy a shelf of them off a liquidation sale.