Ah, see that's the thing.. He is building a cheap computer but i don't know what CPU type. Out of best guess lets say its a top model Pentium with top model mobo, ram and what's not lol I know its a bit hard to pinpoint but that's the best i got.
Get him to download Cpu-z once its built, run it and post back with more details please
what resolution is his monitor and does he have onboard gfx on the mobo?
if not you'll need to put some card in to do the above, and to be fair, he's going to struggle playing at any med-high settings
Ok, well I'll try to give you an Idea, if you click the "more info" link by my avatar then "member config" you can see my PC which could be similar to what he is building. I have a P4 3.4GHz but thers also a 3.6GHz and 3.8GHz, he may also be considering a Pendtium D or Core 2 Duo.
I am running a ATI4670 512mb graphics card which can run Crysis on mostly the medium settings and a few I turn up to high @ 1920 x 1080, I played the MOH Beta and that ran perfectly but I cannot recall the settings I used, but it still played fine and looked good, I play Far Cry 2 on it, similar settings to Crysis, Dead Space settings maxed, L4D 1&2 high detail, Bioshock maxed. COD 4 ran perfectly dont know settings its been a while. I play almost every game @ 1920 x 1080.
Well I guess the point I am eventually getting at is that really the 4670 which now only comes with 1gb DDR3 memory(Make sure it has at least DDR3 memory) for ~$60 and anything above that will be fine for a budget build. Sorry I am an ATI person and i dont know much about Nvidia cards. Another good card to look at is the ATI 5670 for the same price but only has 512mb(which is ok, as I run a 512mb card as well)
Make sure your friend keeps in mind if hes building a new PC, going with really old parts is usally not the best idea, there is a point where you are wasting money on old/poor performing tech, when there is somthing out there that performs much better and costs exactally them same as the older parts do. A balanced needs to be reached because at a certain point even the oldest parts maintain a price that is far to high and make it unsenceable to buy them over newer models.
I finally upgraded to a PCI-Express x16,sata 3 and DDR2 800 LGA775 system.
I am on a tight budget so this was an improvement on my AGP,IDE and PC2100 266mhz system.
And it wasnt just the speed factor; it was the lower prices and better availability of parts.
I got laughed at when I asked for a AGP card in a computer store! LOL
At this point, cpu makers decided to push more instructions per mhz... and the mhz race died and now turned to more cores and better architecture.
PentiumD's (2 pentium4's taped together) not the best but work fairly well.
Those go in the 3.4Ghz
Core2's range is all over the place from 1.8 to +- 3400Mhz
Note that core2 1.8 will kill a 3.0ghz PentiumD
Intel Core I3 , CoreI5, CoreI7 are the latest.
K6 up to 300Mhz (against Pentium 1's and 2's)
K6-2's against pentium2's
Athlon's who killed Pentium3's
AthlonXP's compeating against Pentium4's till HT came out.
Athlon64's were great against Pentium4
AthlonX2's not bad but the core2's took the lead.
Phenom II's are cost effective... but don't hold a candle against a Quad I5 or I7
My advice, you can build a really cheap AMD Athlon II X4 with around 2.8Ghz and a low to mid range videocard.
It really depends on exactly what part he has...
For example if he has DDR2 and an LGA775 motherboard... get a new cheap Pentium Chip and a midrange videocard.