Silvered Bronze Breastplate

About 92s 0c on Beta · Alliance (1 hour ago), 75s 0c on Beta · Horde (7 hours ago), and 75s 0c on Beta · Horde (1 day ago), from player scans. A vendor pays 18s 31c, so the auction house pays 4.8× 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 87s 40c there, against 18s 31c at a vendor.