I would bring the whole issue up with her, maybe print out and take in a copy of your post here. The questions, "why now" and only wanting a "little" back, etc. might help you with whatever you are working on right now?

Think of it like a dream? Maybe you are having a hard time with an issue and wanting to "hold a little back?" Or maybe you were disappointed or angry with your T for something and want to take it out on her a little, hit her where it hurts?

I saw my T for 9 years and paid out-of-pocket the whole time but looking at the number of sessions a year (40?) and the amount I paid, it was kind of like getting a good college education? Look at the total over the year and the lesser amount you might want to not pay and see how little that seems over the course of a year. What would you spent $200-$500 on, specifically? If you don't "need" the money, it might be better in the long run to give yourself the confidence and good feelings that can go with taking good care of yourself? Therapy is a "project" that you decided you wanted to do and are working hard on; do you want to change that dynamic some?

I would definitely make myself discuss my thoughts and feelings about this with my T, would bring up the subject and hang in there with the whole discussion. Make it yours and about what you want for you, rather than what you would like her to do for you (lower her rates). Own what you want, and stand behind it. Whether she will give you a discount and/or how she feels, etc. is not the issue; it is stating what you would like for you and feeling good about yourself, that it is your therapy and you are in charge of and responsible for your life, even this part.