My son has two of them, one he bought recently which is an 07 with a good body and I think he paid £2500 for it which was very cheap, that was in Surrey, we had previously looked at one locally which was older and in nothing like as good condition and that went for £3500.
His other one is an 02 which he bought about 5 years ago, I think he paid about £2500 for that which was also well below what others were fetching, it has given him very few problems but he has just spent £600 + having the chassis repaired and a few other jobs and that was with a local mechanic who charges £150 per day, he has made a super job of it and my son has painted and rustproofed it while the body was still off.
When he first started looking for one there were plenty about in rubbish condition for a lot more than he paid but you have to be prepared to travel, we live in Dorset/Devon and got the first on in Bracknell and the other in Surrey.
I know that doesn't help you a lot but hopefully gives you some idea. If you have a look on ebay you will see what they are asking for them but more importantly if you look at the top left hand side of the page there is a whole list of tick boxes, towards the bottom you will find a couple marked 'Sold items' or 'Completed sales' click on that and it will tell you what they actually sold for. You can also compare the descriptions with yours which should give you a good idea.
Peter