Bailey senator wyoming .. (used prices )

Mary n wayne

I am thinking of buying a used Bailey wyoming 2001 model but how on earth do I find out what its true  value is .Parkers guide does used car values but I cannot find anything that gives used caravan prices at all .Can anyone point me in the right direction
please as I dont want to be ripped off and pay too much for one and if its too cheap there may be underlying problems I guess