Try using fistfuls of cash. The discussion is limited to the most economical of used Porsches, the 944 series, which later evolved into the 968. The car is a good buy because there are plenty of examples to choose from in both turbo and naturally aspirated variations, and although repairs may be expensive, parts availability shouldn't be a problem. As a general rule, cars needing major costly restoration should be avoided, since the 944 will likely not be worth the investment by becoming a collector's car. 1988 and 1989 944 Turbos seem to offer the best bang for the buck, but the 968 is the best all around car, going for between $13,000 and $17,000, about five grand more than a solid 944 T. The article also thoroughly covers the known problem areas for the cars, and kindly provides typical repair prices for things like control arm and clutch replacement.