Runed Copper Belt

About 8s 0c on Beta · Alliance (32 minutes ago), 9s 0c on Beta · Horde (6 hours ago), and 8s 0c on Beta · Horde (24 hours ago), from player scans. A vendor pays 1s 98c, so the auction house pays 3.8× 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 7s 60c there, against 1s 98c at a vendor.