Demonstrator caravans

When is a caravan a new caravan with the full price and when is it a demonstrator model with a price reduction ? My reason for asking is that we have been looking around thinking of buying a new caravan, and two dealers have offered us the 'vans that were on the forecourt at the full price saying that they were new 'vans.  My argument was that they were demo's as lots of people had looked around them and they had been on the forecourt for some months. Who would you say was right ?