yeah, if you really get into computers, you will find that if you build your own you can get it for less $, will usually be a better system, and will be how you like it
but I really agree, if you don't know a lot about computer's, go with a Dell
which system are you looking at? (I'm guessing it's one of the Dimension models) and what do you want to use it for?
if you customise it online, we can help you with choosing the parts, provided we know what you will need it to do