Newbie needs advice ref classified ads, please.

Hi all,

My reason for posting is that my wife and I would like some advice ref the classified ads, we are considering buying a motorhome later this year. We are researching what is on the market at the moment and frankly some of the m/homes in the classified ads seem very cheap! Not a bad thing you might think but how is one to know when it seems too good to be true as an 'outsider' who knows nothing about the correct pricing of m/homes?

What is the done thing with regard to checking the seller and how to transfer/pay funds?

Any advice would by gratefully received, many thanks.

Tim