Great topic Valour! I'm agree with you and all that you said is what I say myself to my friends. I'm agree that the better thing to do to have an "innexpensive" and powerful system is to update it often (don't buy newest,"up to date" parts...to expensive...buy 1 or 2 level under). You already have a compu? (about 1 or 2 years) A lots of parts are still good. So, you don't have to pay 1000$ (or more) to buy a brand new computer. And if you wait to many years and wait to buy a brand new compu, it will cost you 1000$ + every 4-5 years and during this time, you will not have a powerful computer. So, consider to buy for 100$ to 200$ every years and you will always have a good, powerful computer and it will cost less (or the same price but you will have, at every moment, a good computer) than if you changed it just 5 years later.
Personnaly, I buy for about 200$/years of parts.
This is the first specs of my computer... and the changes iI have done on it.
I bought it less than 2 years ago (approximetly 21 months)
AMD T-Bird 1.4 ghz
AOpen (VIA KT266) motherboard
256 meg DDR 266 mhz
Sony CD-RW 16x
SB Live 5.1 sound card
GeForce 2 (don't remember the model) 32 meg video card
20g 5400 rpm HDD
250 watts Power supply
17 inches Samsung Syncmaster 753df monitor
Since this config, I often improved my computer...
Changed CPU to a XP 2000+
BIOS flashing (the board doesn't support this CPU at first time)
Changed the HDD to a 40g 7200 rpm
Changed (again!) the HDD to a 60g 7200 rpm
Changed Video Card to a GeForce 4 MX 420 64 meg TV-OUT
Changed CD-RW to a Mistsumi 52x
Changed the power supply to a 300 watts
Changed (again) the power supply to a 420 watts
Bought a WD 80g 7200 rpm 8 meg buffer HDD (kept the 60g)
Bought a portable rack (and slots) to put my 60g HDD in
Bought another 256 meg DDR 266 (512 meg now)
Changed my 3-wheels mouse to a Microsoft optical mouse
And bought some gadget like webcam, microphone, etc...
That did not cost me too expensive 'cause I sold immediatly all the changed parts to my friends or people who have cheaper parts.
Now, this month, I'll changed my mother board, CPU , video card and memory to a MSI K7N2 Delta-L (probably) motherboard, XP 2500+ barton CPU, GeForce FX 5200 128 meg TV-OUT video card and 512 meg DDR 400 mhz memory.
And my old parts are already sold to one of my friends (he only has a P-II 333 mhz!)
I know that I don't have (and will not have) an UP TO DATE computer but it works fine, is enough powerful and don't cost a lot.
So, consider this before building (or buy) a brand new computer