Hmmm ...
Cant name other sites here, so I'm unsure which ones you refer to as "higher end" ... definitely not all of these sites are alike - even if the advertisers are 500 and up
Generally speaking, depending on the site, a "verified" provider doesn't really mean much - the site's reputation only goes so far.
Deposits: this is up to your discretion, of course. And what you are ok with "losing".
A reputable provider shared this, FWIW:
1. there are a lot of providers - new and not-so-new ones - who are hurting because of the current economy. Like everyone. Generally, biz is down.
2. New clients dont want to give out personal info for verification. Before, the providers could insist on a thorough verification or else. Now, they forego the screening process for new clients (or not as rigorous) in lieu of a deposit.
3. Also, most providers are not able to "make up" for no-shows and last-minute cancellations. Before, they could eat this up as part of doing business. Not anymore. A deposit helps in defraying costs (room, travel, etc)
4. And yes, there ARE a few providers (even well-reviewed ones) who see the writing on the wall, get a bunch of deposits and are gone.
So, yea, it could be a toss of a coin ... hopefully it isnt "heads I win, tails you lose"!
V