Heavy Armor Kit

About 30s 0c on Beta · Horde (3 hours ago), 28s 99c on Beta · Alliance (14 hours ago), and 29s 99c on Beta · Horde (2 days ago), from player scans. A vendor pays 6s 50c, so the auction house pays 4.4× more.

2 recipes: Forceful Heavy Armor Kit and Mystic Heavy Armor Kit.

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 10 brings about 2g 85s there, against 65s 0c at a vendor.