Silvered Bronze Breastplate

About 75s 0c on Beta · Horde (8 hours ago) and 1g 0s on Beta · Alliance (10 hours ago), from player scans. A vendor pays 18s 31c, so the auction house pays 3.9× 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 71s 25c there, against 18s 31c at a vendor.