From what I've read in reviews EROS is hit or miss. Some are legit and some are not and even a verified photo does not guarantee legitimacy. Some people do take a chance on unverified providers it's called "taking one for the team". Have you tried looking on TER using a search in your area?

a few of whom are quality providers.

Just my 2 cents here, but I think you will find the average hobbyist is adverse to risk.  Why pay the $$$($$) unless you know you will be satified?  For the new provider this may be difficult.  Unless she is vouched for by a quality agency, a quality indy, or a quality hobbyist, she will likely receive little attention.  

Once in a while, a hobbyist chooses to risk TOFTT (taking one for the team), or visit a lady who has little, or no information available, with the results often reported on regional boards.

Some of points to remember:
1)Eros, Cityvibe, Exotics World, nmy have desirable pictures, but nothing beats a strong review record, or at least a request for info on the regional board where the lady lives.
2)Some ladies prefer not to be reviewed (a request which I, and some other gentlemen honor).
3) If all you have to go by is the escort mall ad, you should ask on her regional board if anyone knows the woman you wish to see.

EROS has good providers and B&S ones. Your best bet is to get a VIP membership and read reviews for the area that you will hobby in. Go with top rated ladies that have five or more consistent reviews, the chance os a mistake is still there but much less than taking a chance on an unknown. Once you have experience you can try some unknowns, you can find uncovered diamonds that way, but you need to read reviews first and gain experience with what you want. The reviews of cash&dashers or Bait&Switch ladies appear to all read the same, mostly because their tactics are the same - once you have read enough about them, you will be able to sense when a lady is giving you a line during a phone conversation.
I love having an introductory phone conversation with unknown ladies that I am thinking of having a session with. Without fail, the ones that are patient, thoughtful and curteous provide the best time.