It is always appropriate and legal I might add to leave a lady a gift when you have enjoyed her company. On the other hand setting a fee, rate, or any form of prearranged or discussed specific monetary compensation for "sexual conduct" is usually an illegal activity in most states. Although I am not sure what business uncle sam has in my bed I am stating now that I clearly am not setting a specific price or promising anything other than my willingness to get to know you as a mature adult.
Gifts are usually accompanied by a nice pretty card signed in a manner that shows your sincere appreciation and affection and should always be left discreetly for me to open at my convenience. Please don't try and hand me a wad of cash or count out money in my presence. This activity could be deemed as illegal and is also quite classless. I expect to be treated as a lady and in exchange I will treat you as my pampered lover.