As suggested earlier, size of prostate can affect the reading.
Theory is that a larger prostate produces more PSA which is why PSA "density" is discussed in research into less agressive cancers.
PSA density is PSA reading divided by prostate size.
Density under .15 and free PSA greater than 15 percent are often discussed.
PSA doubling time is also an issue. For example if it doubled in a year further investigation would be warrented.
Biopsy is usually not too bad. There can be bleeding after which can sometimes last for several weeks.
The suggestion of a 2nd opinion is also a good one. This can also apply to biopsy results which are subjective.
Most important aspect with all this is selecting your doctor, which can make a huge difference to outcomes.
Lee Nelson in his book "Prostate Cancer Prevention and cure" discusses relevant issues of diagnosis, stage, treatment options, lifestyle changes, diet, nutrition, supplements, exercise, and selecting your doctor.
I'm not familiar with locations, but he mentions doctors at Sloan Kettering, Roswell Park, Columbia uni, Johns Hopkins Uni, and others.