2003 110 defender

Hi all,just joined this forum. I am looking to buy a 2003 110 that,s for sale locally,it has done 86 k one owner and has history. Since I have never owned one and know very little about land rovers I was hoping that the experience of members on this site could tell me what to look out for and what to check before buying. The asking price is £7k. Is there a site where Land Rover prices / values can be checked?
Any help gratefully appreciated
Many thanks Kenny