Common · Miscellaneous · Pet
Same as in Classic Era.
About 27s 0c on Beta · Horde (27 minutes ago), 10s 0c on Beta · Horde (18 hours ago), and 4s 0c on Beta · Alliance (19 hours ago), from player scans. A vendor pays 1s 0c, so the auction house pays 25.7× more.
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 1 brings about 25s 65c there, against 1s 0c at a vendor.
There's no auction house to price until then.
Beta prices — not launch pricesNormal, PvP, and RP open Nov 4