Blue Pearl

About 2g 0s on Beta · Alliance (21 minutes ago), 15s 0c on Beta · Horde (6 hours ago), and 15s 0c on Beta · Horde (24 hours ago), from player scans. A vendor pays 50c, so the auction house pays 380× more.

1 recipe: Flash Bomb.

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 38g 0s there, against 10s 0c at a vendor.