If you really want to save money, look at the Dell Outlet (Refurbished Laptops, Computers & Servers - Dell Outlet | Dell )
I just received my 5510, and it was about half the price of the 5520 that you have shown.
(They do have 5520's on the outlet, I just had limited funds.)
I recommend the 5510/5520 primarily for the small form factor.
Here is their eBay store:
All the Dell Precision laptops are good to to go on Matlab and SW. You really don't even need the newer ones, I believe all the workstations are ISV certified and this is what you need. If money is tight just get a cheap one, you really don't need a precision workstation unless you have some VERY large assemblies and Matlab will run on anything. For what you are doing in College you can buy a high end business grade Dell Laptop for around $250 on eBay from the dell official store (AVOID all the others that claim refurb, the account I posted is the REAL one)and it will rock. At this price who cares if you drop it....