But discussing it over the phone is my least favorite. I even generally ignore it if its a question that's emailed, simply because I have reviews, and I have a fairly simple "it is on the menu, but should be considered dessert" line on my website. Plus, I don't want to email back and forth about that stuff. The truth of the matter is that no I don't know if it will work out, and no I don't want to go back and forth either trying to explain that to you or pretending that I will. Neither of us walk away happy that way, usually. So, I put a note on my website, and raised my rates to the point where it wouldn't be awful if it didn't happen and it wouldn't be awful if it did. There's a price point like that everywhere, I think, you just have to figure it out. So far, everyone seems happy.
You could wait until they get there, and size up the situation if you want to include it in the GFE. However, be prepared to run into a lot of push back when you say no once you get reviews saying you're willing to do it. Especially if your rates are below $300 in most areas. If you are worried about scores, and want it in reviews, be ready to stand your ground, and don't push yourself beyond what you're comfortable with. If you aren't so worried about scores, then you could always ask that they leave it out of the review and say its an invitation only thing.
There is also charging extra for the PSE, or porn star experience. "Sorry Hun, you're too big" seems to be taken better when they're getting $100 back a lot of the time, lol. And if the guy is one of those pushy ones, a simple "sorry I don't discuss donations in appointments/just give me a heads up next time/you didn't ask for it so I'm not doing it" will usually do the trick.
I've done all of the above at a few different price points, and so far the PSE and the waiting til they get there above a certain price point has worked the best for me