I would like a way for OR to calculate an early check in or late check out based on the nightly rate a guest pays. For example, if a guest is staying 7 nights and the nightly rate is $200, I would like a trigger that would calculate 50% of the $200, plus the taxes. So then if another guest rents 3 nights and their rate is $250, then 50% of that, plus the tax. Right now, I only see a way to charge a fixed amount for everyone or a way to charge 50% of the total rent, which is not what I'm trying to do.