Actually, it's strictly verboten to offer an escort money for sexual services. I get paid for my time and that's it; if you start offering me money for a specific sexual act, I'll give you one warning and then ask you to leave. Besides, why would I violate the sanctity of my butthole when I'm already making $175 an hour? Sheesh. I actually like being tied up, but it's not something I do at work because it makes me feel less in-control of the situation.
I actually had no debt after college because I basically made scholarship-hunting into a full-time job. What little was left over I paid out-of-pocket.
Right now, I'm saving about $100 out of every $175. My rent's all paid off for a long time, I'm very cheap (I cook for myself and shop at thrift stores and craigslist), and my main weakness, books, is not an expensive vice.
As far as trends go, the younger guys are generally much more nervous and less experimental. They usually don't want to talk as much, they apologize for every little thing (like laying on my hair or losing their hard-on), and it's generally a big pain in the ass to get them to relax and have a good time. Older guys are less attractive physically but also more fun.
The only big issue with older guys is STUPID FUCKING VIAGRA. Man was not meant to have an erection lasting for the whole of a three-hour session. I get chafed!