I actually think it is pretty easy to beat a Dell in terms of price and performance.. Just use pricewatch and look for a dealer that is running a really good combo price on motherboard, proc, and memory...

About 5 years ago I built my main server at home.. It cost me about 1200$ in hardware alone and the nearest any major manufacturer could get to that for a comparable system was about 1800. What I did was look for mistakes in advertisements.. So in my case I saw a deal where they were selling a socket 850 chipset P4 processor on an asus mother board that did not support the 850 chipset... So I ended up getting an asus p4t-e which at the time was a several hundred dollar motherboard for like 180$.. Pricewatch will delist companies for placing false ads, so if you can spot a mistake you can usually take advantage of it.

In my opinion dell and the other major manufacturers usually use cheap motherboards in their sub $1k price range of systems.. You can have a very fast processor and fast memory with a basic motherboard and your system is going to be slow..