Got the MX300 750GB for $100 at Amazon a few nights ago. Already received and installed it. Wanted to buy two but Amazon had a one limit per customer at that price. I'd probably get a faster drive for a bit more or wait until the bigger drives go back down to $100. Considering I only paid $100 for a 750GB, this does not seem like a great deal. 500GB 850 EVO is just a little more.
I am hoping the 500GB Smasung Evo 850 goes down to $100. Then I'd put that as my boot drive, MX300 as a program drive and move my MX200 500GB to my laptop.