I've done some preliminary investigative work, and in reality, it's not actually quite so simple: there's no 'set' price everyone will pay: each patient seems to have its own payment tolerance.
It appears true that even as low as 105%, some patients will refuse to pay at the base reputation level. At 145% it appears no one will allow treatment anymore, while with the 100 measurements done so far the in-between formula appears linear.
E.g. at 145% price there's a 0% admission rate, at 100% it's 100% and the rate is linear in between (at 130% price you should see 1 in 3 patients continuing).
There's some avenues to explore next;
- study the effects of reputation
- inspect the game's code to see if we can learn more from it.
- take more measurements to get a statistically sound result