Do providers ever enter into long term agreements with regulars?  I am thinking like a regular monthly retainer that covers 2 or 3 sessions a month?

But don't expect her to sign a contract drafted by a lawyer, or a lawyer to draft a contract to begin with..

I was burned in a situation like this, back when I was hobbying much more frequent than I am now.

I suppose trust would be really important.   I would think it would be good for both parties with a steady income stream from a known client for her and a hassle free relationship for him.

It's all about trust. Not done one per se, but just once and recently, due to a phenomenally special relationship, worked toward something like one re regularity and predictable/reliable income flow.  Won't get into more specifics here and now, but it, I think, worked. But that may just be my biased or myopic view.  Legally, they'd not be enforceable (meretricious services are illegal and law won't enforce, in most states, contracts involving em). And even if they were, practically, who would file suit to enforce -- all a matter of public record?

I am currently in a regular monthly arrangement and it is fantastic. It really is a win-win situation in which I have a standing date with someone I like and she has a regular monthly income stream. The trust issue is of course key, but I don't think anyone would enter into an arrangement like this without first seeing the lady several times and judging she was a good fit, which includes trust. The worst downside is that you might lose a month's advance payment if things suddenly head south, but I don't think this happens much.

All court stuff is accessible to the public.  And given the tabloid nature of the topic, it's not far fetched that it all can end up on TMZ or your local 6 o'clock news.

and you like the girl (obvs), why not??!!

If you go thru with it, make sure that you are comfortable with taking a lose if things go south, ie  
1. she finds Mr. Right and moves on.
2. she suddenly retires (several reasons why)  
3. an the list goes on and on........

If you prepay monthly, it's no big loss if she runs. If the arrangement lasts 6 months for so you might have already saved more than a month's fee. In any case, think of it this way. Having her out of the picture, and the arrangement ends, would save you thousands of $. All you lose is a few sessions of sex. Not like it would kill you.

women are like pizza - cheaper and hotter by the slice.

it can be very beneficial for both parties.

Yes! And, I've found the "agreement" is solely based on "trust".