Gotta express some love for the Dell OptiPlex GX110 minitower. Even at five years old, its ease-of-use design for assembly/disassembly made it a snap to add 256MB of SDRAM, four port USB 2.0 PCI board, a couple of disk drives, and a DVD-DL writer. Everything went in without scraping a knuckle. If something in the box fries out, I can easily swap everything out to a "new" box in under 25 minutes.
I spent around $190 in total for the "server" before disk drives and the DVD-DL. I know I paid too much for the SDRAM, but would have paid more for the Dell tower "on the street" from a used shop. Bottom line here is that if you carefully shop, you can find a decent "used" box and upgrade it to a useable config for under $200. Contrast that with a stripped down new Dell or HP box for around $299, but the extra $100 will get you Windows XP Home and a high-speed Celeron processor. There's a lot to be for future-proofing with $100. With a 766MHz Pentium III and a Windows 2000 Pro license, you're about as trailing edge as you can get for functionality on a server. On the other hand, if you're on a tight budget you can buy a piece or two at a time and work on it as therapy.
If I had bought a bare-ones "new" box or upgraded an old one, I would have spent the same amount of money on disk drives and a DVD-DL writer, a total of $170. Depending on the rebate-of-the-week, you can get anywhere from 250 to 360GB for around $100 - pretty insane and it's only likely to get cheaper over the next 90 days. Same with what I paid for the DVD-DL drive - low cost now, lower cost later.
At $499, the Apple Mini is a non-starter for this type of application; you can get a new Windows box for a couple hundred bucks less. I'm still running Win2K Pro. At some point in the future, I may make a move to Linux, but it's not likely. The Linux world has nearly as many flavors as the local ice cream store to choose from.
I spent an additional $110 or so on tools to put everything together. A two-port IOGear KVM switch that included cables cost me around $60. The "switch" is little more than a large "Y" joint with a couple of green lights and three sets of cables coming out of it; one set for keyboard, monitor, and mouse, the other two connecting to the server and another PC. Flipping between boxes is done through keyboard intercept with a quick a double-tap of the scroll lock key. If I want to impress visitors, I can tap another couple of keys to get the switch to autocycle between the two boxes and their displays.
Another $50 went for Norton Ghost 9.0 to "clone" from the Dell's old 10 MB boot drive to a newer 30 MB drive. As a practical matter, that "newer" drive will be shortly upgraded to a 120GB drive. Norton Ghost may be used to conduct automatic backups of drives, but I'm not sure if I'll use it or another program given the system requirements of 9.0 (256MB required).
Finally, I am looking at some future upgrades to my home network and the server. I may add a Gigabit Ethernet card (around $20-30) or two and a GigE switch ($70-80). A GigE switch would improve throughput for local copying and not pound the hell out of my Linksys wireless-B router/4 port switch. µ