Unless you're talking about building a desktop comparable to Alienware, you aren't going to build it for cheaper than you can buy a system UNLESS you have wholesale connections. Now, if you're building it to say you did it yourself that's a different thing altogether. I've been in the computer industry for 20+ years. Computers have gone the way of stereos, tvs, vcrs, etc. They are designed to be cheaper to replace than to repair or build yourself. Computer manufacturers who mass-produce computers now buy components (hard drives, video cards, RAM, etc.) for pennies on the dollar in comparison to what even wholesalers/distributors can sell them for. If you're looking to save money, buy a system.