Oil seepage found, but no oil consumption

I recently purchased this vehicle, have been driving it for a couple of months and have put on about 3,000 miles.
Took it into the dealer for a oil change and inspection. All was well, but they noted that I had an oil seepage that the technician didn't identify from where, and I would need to bring it in for a diagnostic visit ($125.00) so they could identify where the leak came from. They stated it was category 3 (1-5 range). I asked if the oil was low when I came in and they told me it was not. I am wondering if this is just a high mileage issue that I should monitor for oil consumption, or should I get the car in and pay the diagnosis fee and then pay for whatever repair is necessary? There does not appear to be any performance issues, and I have not seen any oil stains under the car.