Small Leather Collar

About 85c on Beta · Horde (6 hours ago), 86c on Beta · Horde (23 hours ago), and 65c on Beta · Alliance (1 day ago), from player scans. A vendor pays 33c, so the auction house pays 2.4× 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 10 brings about 8s 8c there, against 3s 30c at a vendor.