Whether you are purchasing privately or from a dealership, it is important to do your homework on the car you want to buy. If you have found an example you are interested in, look at other examples on sale to see how they compare in terms of price and use the Honest John Used Prices guide to see what is a fair price here: www.honestjohn.co.uk/used-prices/

Most sellers are prepared to negotiate to some degree, but it is important to be reasonable. Make a fair offer and let the seller respond. If they are not prepared to meet you somewhere in the middle or offer any negotiation, leave them with your offer and walk away - if they are genuine and your offer is fair they will come back to you.