The much anticipated Guardians of Harmony set looks to be starting it's big Amazon flood on the 12th of July! Celestia is now priced at $20 and available for pre-order from their main site. Unfortunately, Nightmare Moon is still unavailable outside of ridiculously scalped prices from 3rd party sellers, so it's best to wait on her. It wouldn't be too surprising to see her join Celestia very soon though.
I have to admit, I haven't bought many pony things since Funko and 4DE went on hiatus, but I'll definitely be picking these up. Expect full reviews once they ship!
(Update: Already sold out at the July release and $20 price point. That was quick!)
Thanks to micheal for the heads up!