A compression test, as many have stated or alluded to, is one of several diagnostic tools to help determine engine health. On a typical Lycoming, your readings will generally be 72 or more on a high-time engine, and 76 to 78 on a low-time engine ... assuming proper break-in and no problems, of course. If your readings are above 78 (or possibly 79 with a properly calibrated differential compression tester), that cylinder is likely burning oil (the oil masks the leakage past the rings during the check). A good technician will often learn more from listening during the compression check than from reading the numbers.
The above being said, a 60 reading is still a 75% cylinder, so I would have no hesitation regarding a reading of 71. When you find an aircraft you are getting serious about, if you're lucky the current owner has a track record of oil analysis and decent engine records, which will help you determine engine health.
Please keep in mind that as expensive as an engine is, it's really easy to spend more on avionics, or paint and interior. If you find a clean, relatively low-time, corrosion free, hail free airframe with the avionics you want but a high-time engine, don't let the engine scare you away ... you can replace everything firewall forward on the right aircraft and end up with a real gem, but if you have an airframe that's corroded you have nothing.