Plans: Mighty Iron Hammer

About 6s 0c on Beta · Alliance (54 minutes ago), 8s 0c on Beta · Horde (7 hours ago), and 15s 0c on Beta · Horde (1 day ago), from player scans. A vendor pays 5s 0c, so the auction house pays 1.1× 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 5s 70c there, against 5s 0c at a vendor.