Threshadon Fang

About 21s 0c on Beta · Horde (5 hours ago), 21s 0c on Beta · Horde (22 hours ago), and 5s 0c on Beta · Alliance (24 hours ago), from player scans. A vendor pays 3s 17c, so the auction house pays 6.3× 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 1 brings about 19s 95c there, against 3s 17c at a vendor.