Stranglethorn Seed

About 5s 50c on Beta · Alliance (33 minutes ago), 20s 80c on Beta · Horde (7 hours ago), and 25s 80c on Beta · Horde (24 hours ago), from player scans. A vendor pays 1s 0c, so the auction house pays 5.2× more.

1 recipe: Lesser Wizard Oil.

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 1g 4s there, against 20s 0c at a vendor.