Whispering Vest

About 20s 0c on Beta · Horde (6 hours ago) and 33s 0c on Beta · Alliance (7 hours ago), from player scans. A vendor pays 5s 47c, so the auction house pays 3.5× 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 19s 0c there, against 5s 47c at a vendor.