I think as above, buying a 10 year old+ big beemer with high miles could land you in all sorts of trouble with reliability/replacement of worn parts - that seems like really bottom end price, has to be a reason for that.
Actually just did a check, hasnt been taxed for the last 3 months, MOT expires in November and has advisories around the brakes and an oil leak. It has failed 4 MoTs since 2011 then passed with advisories after that. The oil leak has been present since end of 2013...