Runed Copper Belt

About 9s 0c on Beta · Horde (4 hours ago), 8s 0c on Beta · Horde (21 hours ago), and 9s 0c on Beta · Alliance (22 hours ago), from player scans. A vendor pays 1s 98c, so the auction house pays 4.3× 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 8s 55c there, against 1s 98c at a vendor.