Those machines go for those kind of prices - of course you'll get some people who would never pay that, and others do. Me? I'd offer £300-325 max. Why? Because these days a lot of people are clearly trying to offload their PPCs and are switching to the much faster Intel machines so there are a lot of those around. A 1.67 will still be pretty fast - it depends on your needs. But, there's no guarantee so it's a bit pricey. Play with it first is my advice.