DDR3 RAM 1113: Either 4GB http://www.newegg.com/Product/Product.aspx?Item=N82E16820313072 or 8GB http://www.newegg.com/Product/Product.aspx?Item=N82E16820313123
One of these SATA Hard Drives: http://www.newegg.com/Internal-Hard-Drives/SubCategory/ID-14?Order=PRICE
Radeon HD 7850: http://216.52.208.185/Product/Product.aspx?Item=N82E16814131473
500W Power Supply: http://216.52.208.185/Product/Product.aspx?Item=N82E16817101011
One of these cases: http://216.52.208.185/Product/ProductList.aspx?Submit=ENE&N=100007583%20600006302&IsNodeId=1&Description=case&bop=And&Order=PRICE&PageSize=20
Some DVD burner: http://216.52.208.185/CD-DVD-Burners/SubCategory/ID-5?Order=PRICE
Windows 7 64 bit: http://216.52.208.185/Product/Product.aspx?Item=N82E16832116986
Wouldn't you be better off buying an AM3+ motherboard? They are almost all(if not all) backwards compatable and support AM3 socket. Would give your friend an upgrade path for the CPU down the line if he chose to do so.
And do try to use pcpartpicker.com. I cannot explain the level of hatred I have for long lists of links without any product names. If you just listed the product names then I would have no issues telling you what I thought about it. In terms of this build, I'm not entirely sure why you would bother with it. I mean, it's okay. It'll run quite a lot of stuff, but that is primarily attributable to the fact that it's got a 7850 stuffed into it. You'd be better off, in the very least, to upgrade to a socket AM3+ board with a 970 chipset. These boards typically support more and faster memory, as well as SATA 3.0 6 GB/s. The next possible upgrade route would take you to a Phenom II instead of an Athlon II. The phenoms are just that bit better. It isn't an absolutely huge margin, but you do get what you pay for. Plus the unlocked ones overclock very nicely if you can get a board with adequate power management. For that, check out the Gigabyte 970A UD3. It's about $77 and it has an 8+2 power phase. The Unlocked Phenom II X4 965 BE is about $89. 8 GB of DDR3 clocked at 1600 MHz should cost about $42. And a 1 TB drive can be found for about $60 at any point in time. It just depends on what brand you prefer.