The best advice you have is above, TAKE YOUR TIME, and it is a buyers market. I got all excited a while back and felt I had to have a 3lt E85 Z and saw a lovely one advertised 350 miles from home, it had just under 60,000 miles on it. It was on ebay and the bidding was quite low to start, before doing anything I spoke to the owner and he sold me a lovely story of heated garages and being the most loving of owners with endless service history. Well long and short of it I got carried away on the bidding as someone else was also sold on it. I won the car for just over four grand and happily trudged off to North Yorkshire. No heated garages just a dodgy estate in the middle of Harrogate, why I didn't just get a taxi back to the station I will never know. The car looked the business but could not test fully as the dodgy git selling it said he had to get back to work asap so driving around in traffic. Sat Nav set up off I go homeward bound, get to a dual carriage way n open her up, she just cut out and I drifted into a layby, rang the seller and he said just start it again and it should be fine. It did start and as long as I kept below 3000 rpm it was fine, at this point the seller must have pulled out his sim card and thrown it in the ditch, end of contact. Well the long and short of it is that it got me home and we formed a bit of a bond, slightly wounded the car brought me back the 350 miles safely, the full service history was all fake and there were a multitude of electrical problems. Never realised how difficult it was to report a bad seller or get a refund on ebay.
The engine problem was air flow mass sensor and most of the problems were just fiddly and with the help of many on this site I now have a low milage z that I absolutely love but I could have saved myself a hell of a lot of stress by being more patient.