Colin Dowling's answer is promising as far as it goes, though it's certainly not a universal truth… Often, the $500 escort is the most dangerous in terms of discretion – paid enough to know the client must have the money to burn, but not necessarily enough to forget said client's address/name/etc. Speaking with off-duty escorts, it is not uncommon to hear the occasional namedrop/hint of a celeb encounter.
But it's definitely true that looks would not be a primary differentiator. Rather, based on the numbers listed, I would venture the following differentiation:
- At $50, an escort is likely walking the street, and the session will take place in a car, should a suitably private parking spot be located. Such an encounter is relatively high risk in terms of health, hygiene, and law enforcement implications. On the "pro" side, prostitution hobbyists who enjoy "cruising the strolls" enjoy the thrill of the chase, of identifying a working girl, successfully negotiating terms, and completing the encounter without a robbery, injury, or arrest taking place. Attractiveness, mode of dress, age, etc will vary widely with each encounter, and unless numbers are exchanged at the first meeting, it is unlikely a john will see the same girl twice. Both client and escort are typically on "high alert", just plain "high", or both.
- At $500, an escort is more likely visiting a client's hotel room or home, or hosting from similar. Escorts vary widely in appearance, though they tend to be of very good hygiene, and above-average fitness and general health for their body type. Sessions will be much longer than a car date, typically 1-2 hours at this price point, with a "generous, non-clock-watching" hour being fairly common – at $500, escorts are less likely to be stacking appointments back to back unless they are on tour outside their home city. Skill in conversation, massage, and other pre-play activities will still be inconsistent here – some escorts will be very intimate and deeply engage/roleplay with clients, while others are basically working off the visual and "endgame acrobatics". Law enforcement risks are much lower, since the activities happen "behind closed doors", and typically do not affect the surrounding community in a visceral/meaningful way. At $500, escorts also are typically well known and reviewed/vouched for by the hobbyist community across sites like http://myredbook.com, http://www.theeroticreview.com/, or http://eros.com.
- At $5000, an escort is likely to be in peak physical condition, and represent the epitome of conventional beauty standards. Sessions can be anywhere, but are likely multi-hour or overnight/weekend getaway affairs (travel and accomodation costs are, of course, not included). Escorts tend to be older (without looking it), wiser, and able to hold up a solid conversation with just about any type of client, from the most awkward nervous silicon valley java developer at a newly-acquired startup, to the Type-A amateur sommelier CEO of the acquiring Fortune 50 megacorp. Law enforcement involvement is extremely rare without severe cases of abuse/drug or human trafficking, etc – these workers are pulling in enough to pay lots of taxes, and even be valued members of their community. Such escorts will both have impressive rolodexes of regulars, and behave with the utmost discretion, as they themselves will have a great deal to lose. The big exception here are "managed" escorts – agency fees can be just as high, but with so many additional people involved (management, security, drivers, etc), fewer assumptions should be made about the quality of the experience or the level of secrecy provided (as numerous congressional and celebrity "outings" have shown – these incidents are almost always agency-based unless the client is caught "red handed" somehow).
With some apologies for the late (early) hour for my wording (I tried to keep it fairly neutral), I will also say that the above "vaguely" maps across escort and client genders and orientations – though the non-heteronormative prostitution market is much less established/economically stable/researched to date.
What's the difference between a $50, $500 and $5000 a session escort?