You also have to consider what bells and whistles come with the Alienware desktop compared to the one you build. Don't just compare parts.
Like?
Alienware computers constantly have that disgusting case, but every model above $800 has an i7.
alienwa-
forget
Find some dumb brand like alienware and get the specs on the specific desktop. Match up what it would cost side by side of if you bought the premade, or made your own with the same parts. Then use the leftover money to show what you could improve.
Alienware desktops.
Okay, alienware seems like a great example, thanks guys.
Anything on the lower end?
I suppose this is a bit harder to find, but I want to show that my 'presentation' could even help someone whose not looking to build the best gaming computer per se, who doesn't know much about computers, and just needs something to like, browse the web and write documents.