You should consider to upgrade the laptop with a SSD harddisk. For your SQL performance
But that will considerably increase the cost.
A 80 GB SSD will cost $200.
And a 80 GB will be rather small for Windows + SQL. (StarCraft II already is 8 GB)
Videocard speed is another issue. SCII doesn't have very high system requirements, but running it at HIGH DETAIL settings will require a videocard, budget laptops just don't offer.