It's all negotiable, fun, dinner, more fun, sleep time, fun, breakfast, etc. The only thing I would recommend you is to meet the guy first and do an overnight after you know there's chemistry.
I know so many escorts who retired with nothing but the stories... It's never too early to start saving money.
You're smart, I usually but shoes at DSW.
Make him work for $900, he'll be more likely to save it or use it for something not to frivolous as Balenciaga.