AnandTech: HP DX5150 – OEM plus AMD. A good review of a business system. Interesting to see how performance has really converged. If you upgrade the video card, then you have a very high performance machine.
They recommend the DX5150 X2 3800+ “Smart Buy”:http://h71016.www7.hp.com/dstore/MiddleFrame.asp?page=config&ProductLineId=429&FamilyId=2178&BaseID=16561&jumpid=re_R2515_store/smProdCat/BusinessDesktopPCs/sku_dx5150. This actually has a Athlon 3800+ X2 in it and is called SKU PZ635UA# ABA and it is just $950. Amazing when you consider the CPU alone costs $320 at retail. Yes, it has just a 80GB hard disk and a CD-RW/DVD drive, but you can get a 300GB hard drive for $125 and a very fast burner for $55, so it is still an amazing bargain.
Not a bad price and then you slap a new video card in.