I've said this before I'll say it again.. If you can install video cards, upgrade ram, replace an HD, and put in a new cdrom drive.. You can build your own computer.
Best place to look for stuff for price is http://www.newegg.com
Just for instance. buying the parts to build a system yourself.. You can purchase the EXACT same parts the alienware uses (Alienware even tells you exactly what they use on the "customize" section of thier site) Anyway...
Here's the specs for the system.
(These were pulled from Alienware's site)
AthlonXP 2800+ "Barton" CPU
Asus A7N8X - Deluxe Motherboard
Forton Source 530w PSU
1GB Corsair matched pair (twin 512Mb) DDR 3200
2x80gb Seagate serial ATA drives - Raid 0 (total 160Gb HD space)
Gigabyte Radeon 9800 Pro 128Mb Video
Sony 16x DVD
Lite-On 52x/32x/52x CDRW
Sound Blaster Audigy 2 Platinum
Windows XP - Home edition
(I didn't use specific items for mouse, keyboard or case, BUT I tacted on $300 to the buildout price that I got from Newegg to include these)
Price from Newegg including shipping and $300 for Mouse, Keyboard, and Case: $1882.97
($1582.97 before $300 expense add in)
Price from Alienware NOT including shipping: $2437.00
That's almost $600 savings for the same components, AND I put in a higher wattage PSU (530w vs 420w). The only thing you lose is the alienware case (which I must admit is pretty cool, but not $600 worth of cool) and the year of phone support from alienware. However, all of these manufacturers warranty thier products for at least a year. In the case of the Corsair Ram, it is warrantied for life. the $300 that is added into will get you a REALLY nice case plus a mouse plus a keyboard that YOU LIKE, and still have some left over to add in some lights, etc.
as far as cases are concerned, check out http://www.thermaltake.com
. Thermaltake's cases are pretty cool and you can get matching keyboards and mice for them too.. (all of which are available at newegg.) an all aluminum case (Xaser III series) with matching keyboard and mouse (with mousepad) is $195 - $105 less than I added on that you could put back in your pocket.
What it boils down to in all of this is.. Alienware uses quality parts, but you pay a premium because they build it for you and slap thier name on it. You can have the same thing for a better price and have the added benefit that you KNOW your system, cause you built it.. *and you can brag to your friends* lol..
Hope this helps somewhat.. Have a good one..