Of course you could, but it all depends on what actually needs doing (ie you "need" brakes that work) and what you feel you have to do to keep yourself happy (ie the seats could do with recovering, but don't actually have to be to drive the car safely). Also, it depends a lot on what you are willing/able to do yourself. Labour costs mount up quickly. I spent £3k on getting the car painted and £1.5k on new seat covers, carpets and door card skins, so everything else only came to £3k. Mind you I might have to rebuild the gearbox yet, that's the fun with a 40 year old car, you never know what is going to need fixing next!