Not sure if this has been mentioned else where on the forum.
I recently got one from China and it came with a SD card full of games, although I will be adding my gg2sms set to the card as well.
I paid £33 for mine and it's taken about 10 days for delivery. You might find it cheaper off other sites but I got mine of eBay who I have bought other things from, so is trustworthy.
Tested mine on a retro duo with a genesis adapter and then a master system adapter and then the everdrive on top of that abit of a stack but it turned on and I was able to play a game straight away.
One of the things that I noticed that wasn't on the Chinese version over the original everdrive was that the action replay code part isn't on it which is a shame, I will test my action replay cart out to see if I can get it to work with it.
This has to be a good cheap way to play those hard to find or expensive games on a real master system .