Stranglethorn Seed

About 25s 80c on Beta · Horde (9 hours ago) and 2s 0c on Beta · Alliance (12 hours ago), from player scans. A vendor pays 1s 0c, so the auction house pays 24.5× 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 4g 90s there, against 20s 0c at a vendor.