I sold my BBC a few years back for £30 with a load of games and the cassette deck I used. It was still working fine. One thing it had over modern computers was that it started up instantly, but then you had to load some software to do anything practical. I never got around to getting a floppy drive.
Now someone has gutted an old BBC and installed a 600MHz PC with a 40GB hard drive as shown here. He runs Linux on it and can even run old BBC games via an emulator. It's a very neat job using the original keyboard and not making extra holes in the case.
I'm not into that sort of hardware hacking, but I may be building a new PC soon. The power supply in my big tower may be dying and it's very noisy. I've long lusted after something smaller and quieter. I've now discovered a couple of possibilities to remedy this. The Aspire X-QPACK is quite funky with it's transparent panels and carrying handle. There's also the Antec Aria is more restrained. Both will take my current components with space for extra hard drives. Both cost around £70, which is not cheap for a case these days, but worth paying for the benefits. For that Antec throw in a card reader as well. I'm mulling it over for now.