I get asked this question a lot and it dipence on a lot of things. First of all if you are building a super hige end gaming masheen, you can get a very lage reducon in price then buying the same rig off some one elce. But for a standerd home computer im not shuear so im going to test it out.
disclaimer: All prices listed are prices at the writing of this post and may have changed by the time you are reading this, although in theory this rig should work I have not tested it and therefore is completely theoretical.
I have solected the HP Pavilion P6630uk to test this out with as it is a mid range computeer, nothing speshal, but also nothing extreemly spectacula, at the time of rigitng this post it was priced at £493.92. Lets see if we can build more or less the same computer for less than this price.
It has a AMD athlon II x4 runing at 2.9GHz, I cold not find one of them but we can go better with the Athlon II X4 645 running at 3.10GHz for £75.55.
Now we know what sort of proseser scoit the motherbord will need to have(AM3), we can find a realy cheep mother bord, the bord i have solected is the ASUS M4A78LT-M LE priced at £38.98. So the mother bord and proser combanaton total price is: £114.53.
The HP has 4gb of ram so i have solected 4gbs of Kingston ValueRAM DDR3 for £23.73. total price so far: £138.26
The hard drive in the HP is a 640gb dirive, found a Western Digital Caviar Blue for £30.95. totoal so far is £169.21.
Thegragics card in the computer is a nVidia GeForce 210, Palit do one for £38.90. total after that is £208.11
so that is realy the main parsts of the computer for only £208.11 the other acsesarys that are needed are a optical drive: this LG will do the job fine at only £12.29. most cases will be fine for this build the Cooler Master Elite 335 shold be fine therfor priced at £35.59 ans a basic 500w PSU shold be ok to power the thing this one shold be ok at only £13.49. So for the total cost of the hardwear it is only 269.48.
Personaly I think that alot of computers cost comes from the OS wich is why i use linux, a typpe of free oparating system(But that is a compleatly difrent post altogether). To be fiting with the chalang i set my self cost of the OS needs to be included. I have cosen to use Microsoft Windows 7 Home Premium 64-bit OEM for this build(£70.99). It is the same OS that is one the HP computer, just the OEM vershon, this meens that it was bort in mass, sort off. but also that is a compelaty difret post.
Altogether the cost of this similer computer if self built is £340.47. £153.45 cheeper than if bort from HP. but with a self build you dont get alot of things that you wold get if you bort it. First of all it takes quite a bit of time to build, somthing you wodnt need to wory about if you bort it, techinacal suport is harder to get hold of if you build it your self. so it is cheeper to self build(most of the time) but its also a bit of a hassal building the thing.
Thank you for reading.