Lightning Eel

About 15c on Beta · Alliance (3 hours ago), 55c on Beta · Horde (9 hours ago), and 55c on Beta · Horde (1 day ago), from player scans. A vendor pays 10c, so the auction house pays 1.4× more.

No. It is in Classic Era too, with the same item level, vendor price and stack size.

Sell it on the auction house. After the 5% cut a stack of 20 brings about 2s 85c there, against 2s 0c at a vendor.