I paid $289 (you can probably find them for less) for mine. It is very accurate. Can be picky about the type of ammo though. But once you find what it likes, no problems. I've read similar comments on the Ruger MkII forum.
Mine seems to like CCI MiniMags. Shoots them straight and no mis-feeds, or failures to eject. I've also noticed the CCI's seem to burn pretty clean. I had problems with Wolfe Target, Federal Gold Medal, Winchester Target and, although not as much, the Wal-Mart Federal Value Pack. Quite a few FTE's & FTF's and lots of fouling. I also went with a dry lube after I clean which I read on the Ruger forum as well.
The mag release is a button style just behind the trigger and forward of the grip like most of the other autos I am familiar with (never seen the one on a MKII). I put the Ruger wood target grips from on mine which makes it a little tougher to reach, but that was my choice. No problems reaching it with the stock grips.
Overall, I'm happy with it. It's a great target shooter or plinker, whatever you like. I put a red scope scope on mine and off a target rest, it's dead on.