Big Bronze Knife

About 38s 0c on Beta · Horde (9 hours ago) and 39s 0c on Beta · Alliance (10 hours ago), from player scans. A vendor pays 14s 26c, so the auction house pays 2.5× 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 36s 10c there, against 14s 26c at a vendor.