Shiny Fish Scales

About 8c on Beta · Horde (8 hours ago) and 7c on Beta · Alliance (10 hours ago), from player scans. A vendor pays 7c, so the auction house pays 1.1× 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 20 brings about 1s 52c there, against 1s 40c at a vendor.