It's hard to come even close to the price of a pre-built when you're looking just at the price of hardware now a days!

Then, add in the price of the OS, included software, Tech Support, and warranty, and it becomes even more lopsided.
However, when you build your own, you know exactly what your getting, you don't get all the bloatware, and you have the pride in knowing you built it.
Personally, I have 5 in the house I built, and 1 HP that I stripped and loaded my own OS and software on.
(HP said it couldn't be done!
) I will be upgrading 3-4 of them this summer (including the HP) and building another for the wife out of the parts left over.
Harder