Elixir of Agility

About 24s 90c on Beta · Alliance (1 hour ago), 15s 75c on Beta · Horde (7 hours ago), and 18s 75c on Beta · Horde (1 day ago), from player scans. A vendor pays 2s 0c, so the auction house pays 11.8× more.

1 recipe: Quickdraw Quiver.

It exists in Classic Era too, but with different numbers there.

Sell it on the auction house. After the 5% cut a stack of 20 brings about 4g 73s there, against 40s 0c at a vendor.