New mainspring during light service

[AlpeDHuez]

I‘m moving towards buying my first 5-digit Rolex purchase and am eyeing a 16570. My preference would be one from the 2000-02 timeframe with a holes case and box and papers.

Found one that fits the bill, but am somewhat puzzled by the description, pictures pasted below. The seller (a reputable dealer) states a partial service had been performed during which new gaskets were put in, the case was lightly polished, and the mainspring got replaced. Price is a hair under 8k USD

Seeking advice from the experts: what questions would you ask? Based on pictures, the polish looks good, but I’ve never encountered a partial service that replaced the main spring. I’m fully ok to pass and wait for the next one, they do seem to come around frequently, but wanted to get a perspective.

Thanks!