What are your fees?
Tips at time of donation. You decide.
If payment is required to use a service then that payment is not a "tip" - it is a "fee". Anything over the required payment would be a "tip". This FAQ answer implies that the required payment is zero, which, it turns out, is false.
There is absolutely nothing wrong with charging a fee for a service, but there is something wrong with lying about it.
There is absolutely nothing wrong with charging a fee for a service, but there is something wrong with lying about it.