Inferno Cloak

About 18s 0c on Beta · Alliance (3 hours ago), 1g 0s on Beta · Horde (9 hours ago), and 1g 0s on Beta · Horde (1 day ago), from player scans. A vendor pays 8s 31c, so the auction house pays 2.1× 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 17s 10c there, against 8s 31c at a vendor.