Awesome, that's really great that they gave you that, I'm proud of you. =D
For free that's a great deal, lol, otherwise Alienware tends to be you paying lots for the name, not the hardware. You can build a box close to that one for $2k without all the custom Alienware stuff and with substitutes in their place.
Here's my box:
http://neonpulse.net/2006/04/02/new-computer/The only changes are that I got an ergonomics keyboard, BenQ FP93G X 19" LCD, 160GB SATA drive, and I O.C. my AMD Athlon X2 4200+ to 2.7GHz.
In all I've put less than 2k in it for sure, maybe around $1,500.
Just make sure that you know how to fix it yourself. XD
...but then...you don't get the sweet Alienware case, lol.