I was in a similar situation with a PSA of around 4. I waited for a year doing several tests, usually in the 3.0-4.5 range and fluctuating. In the end a urologist did an ISOPSA test that came back high, biopsy showed Gleason 4+4=8 (downgraded to 3+4 at pathology). You could do an ISOPSA or PSE test before deciding on biopsy.