that's a very expansive question..
what state is your car in. does it need any body repairs. have you checked under trim to see if it needs rust treatment or any other extra prep work. do you want bare metal/windows and interior out, or just a mask up/flat down/blow over.
id say you're looking at a bare bare minimum of £600 (if you know the right people) and upwards of 3 grand at the other end of the scale.
you really need to get to a couple of bodyshops and have a chat with them, to see what's needed and what's best for you.