G'day Becboo, We have an 01 Rover Ultra which we bought in oct 09, we paid 15k. If i sold it now i'd be thinking around 12-13k. Mind you, i have seen some ridiculous prices for that vintage hard floor campers. Some people seem to want near new prices for them. They are a great product, we have no dramas with ours and its in schmikko condition.
My F-I-L just brought a 2004 pioneer camper with battery system, two 60ltr water tanks, full annex, kitchen, gas bottle holders and storage box for 14k.
I would have thought around 9 - 10 depending on what options it has.
I've got the oct 2001 price list in front of me and a bog standard challenger went for $16330 inc g.s.t
Hope this helps you!