Just thought I'd give an update. We bought a used car this morning from a main dealer. He wanted 7500 but I haggled (7k was my limit). However, the best I could get him to (and I generally pride myself on being good at this haggling lark so it was disappointing) was 7250. At that point I left, saying that I wasn't prepared to pay that. I think the fact that he let me go shows that he knows he would shift the car easily to someone else. Anyway, after some discussion we decided to buy it anyway at that price because it was a very good car. He said that they are low on used car stock. I guess if no on is buying new cars then they are not trading in ones that are a few years old (this is an 06).
Depends on the car of course but broadly speaking 7250 doesn't sound bad at all for an 06.