It's only £695. And that's the last reason you should buy it.

The Commodore 500 was part of the CBM-II Series - an attempt to produce an update for the original Commodore PET and seen as the company's last chance to break the business market, which was in the process of being owned by IBM and the clones.

It ran a MOS 6509 processor and supported up to 896K RAM. Mosst of this wasn't actually directly available to the version 4.0 BASIC the machine came with, but could be accessed via machine code and bank switching.

The machine was also something of a curious hybrid as despite its price - £695 is around [[695|1983]] in [[now]] - it was primarily aimed at home users, with the same SID sound chip as found in the popular Commodore 64, and two joystick ports. 

It also came without a monitor, but could support a regular colour television via an external RF modulator. The 500 even had a more home-friendly 40-column display, compared to the more business-like 80 columns of the 600 and 700 models.

None of the CBM-II line sold particularly well - Commodore relaunched the sibling 700 model at least twice. Apparently a lot of stock was shifted during the "Great SBM-II Series dump of '84"[source: http://www.zimmers.net/cbmpics/cb700.html].