It's a good deal.
The SSD is probably worth around $250 and the memory around $100. You have to take into consideration that the SSD is replacing a 500GB hard drive (or thereabouts) that would be in the computer otherwise. I'd put a value of $50 on the 500GB hard drive.
Not sure how much memory that system comes with from the factory but if it's 8GB, then another 8GB would cost you around $50.
So the total benefits of the upgrades would be $350-$100 which would give you $250. Deduct $250 from the price and you get $800 for the base system. It's a good deal but nothing stellar.