The most I have ever paid was 350 for Ashley of Max Angels (reviewed) because she had been on my hot list for a long time. A very good shag, but not going back: is a shag ever worth 350?
There are a few girls I have punted at 300, but they have been one offs: tick them off my list once and move on. Eg Bree, black hottie in Shoreditch, Carlie of Hamilton escorts, Amanda Banks (all reviewed here) plus a few others now retired. Of these, only Bree was a (very) good shag. The other two were disappointing, proving there tends to be little correlation between price and quality. I have had much better punts around the 200 mark, which tends to be where most of my punts are.