Need new system, but have no experience. help!

Help! I am in desperate need of a new system of my own so I can stop relying on my roommate's computer and my office computer. Trouble is, I don't know much about them. I have configured a system on Dell (many times hoping the price would drop but it hasn't) and I know what I want from them. What I don't know is how to compare that with a custom system and get the same or similar things. My roommie's computer is a ShuttleX and I really like that and I'm willing to try and cobble the thing together on my own (i'm not too bad at that), i just need to know what to get. I'm also probably going to have to get components in stages as I can afford them, so I don't mind getting it one bit at a time. I've got a configuration from dell to use as a starting point and if anyone could point me to the right components, I'd be thrilled. Thanks!

"if I could just find the 'on' button...."

why would u get a pc from dell?

yes i agree with all of what u had to say. but also company's like dell etc over charge quite alot well here in uk they do.