I'm thinking about making a carpc w/touchscreen for my car someday, but I wanted to ask what all have you guys put together for yourself or friends/family that was cheap but relatively new, like Athlon XP and newer.
Cheapest system I have built recently is a VIA EPIA 5000-based media server (For an old MP101 music player). The case came with exterior brick-type power supply, a 250GB IDE drive with just 2MB of cache (cheap) and I had half a gig of PC133 lying around. I had a spare Win2K Pro licence, and an old slimline optical drive from a dead laptop. I also had a spare 802.11g PCI card left over from a recent Gigabyte board build - so the entire thing cost absolutely bugger all.
From memory, the case and PSU was $80 and the motherboard/CPU was $90, total, delivered.
The real nice thing about this system though, is that it draws about 17 watts of power when the IDE drive is powered up and it is serving music. When the drive is asleep, it draws just 11 watts. The power brick barely gets warm. (The system is also fanless, as I removed the two tiny 40mm fans and hence it is utterly silent, except for HDD access.)
That means it costs just $2 a month to run 24/7, as opposed to the old slot-A Athlon 650 it replaces, which, with 3 HDDs installed, averaged about 150 watts, and hence $20 a month in power.
That means I'm saving money $18 a month in just 9 months from now.