Similar to the {BTHOSTFEE} email field could we have a placeholder that displays the value LESS any credit card fees. It would be nice to have one field that will always display the OTA commission.
Unfortunately, this is not possible. It would be misleading, because in most cases we have no way of knowing what the credit card fees are. We also don't necessarily know that we do or don't know what all the credit card fees are, so it wouldn't even be possible to add a definitive warning. It would be kind of guesswork, which wouldn't be terribly helpful I'm afraid.