How would you read a doctor who refers you to urologist, who recommends biopsy for any psa 2.5+. My dr. Told of latter says, "buyer be aware."?

Unclear. My training focused on a change from baseline rather than a specific number. For instance if your psa has been 1.0 or close for a few years and in jumps up by. 75 in one year, that is worth an ultrasound. Then depending on those findings a trip to the urologist for potential biopsy. Any other thoughts from collegues?
Depends. How old are you? What was your psa a year ago? Has there been a recent and rapid increase in your psa level? Is there a nodule in your prostate on rectal examination? It would be prudent to follow the advice of the urologist.
Depends. I recently referred a patient with psa 2.6 due to exponential doubling of his psa and biopsy was positive for cancer. Problem now is he has it and knows it, but too soon to do anything about it according to all experts involved. I refer all psas doubling and those especially when associated with nodules on dre. If there is an acute jump, I usually do a trial of abx to rule out a prostatitis.