Reading reviews on TER, I see a significant gap between the bid (on the review) and the ask (on the ad).
One of my first lessons as an apprentice monger was to not haggle unless you're at a Nevada Brothel.

In a Nevada Brothel, when presented with the suggestion of a $3,000 jacuzzi party,  you reply with "That's more than I had planned to spend."

Is there an equivalent phrase in the TG Escort world?  Most of my experience is been in Bars/Clubs/Strolls where you  aren't buying sight unseen.

Every provider I know, from the ones that mentor me, to ones that I mentor, any sort of 'bid' or 'haggling' with a new client is seen as boundary pushing, indicating a possibly dangerous or difficult client, and doesn't fly at all. It's either pay my rates and deposit or stop wasting my time. That said, I do entertain non-standard agreements with long established clients; but with new clients, it's an absolute no.

Meet her in person and decide immediately what you want and the limit of what you'll pay. Then tell her what you want, explicitly, but not what you'll pay. Ask her if she's OK with it, and how much she's looking for. If her response is at or within your limit, give it to her and take off your clothes. Otherwise ask if she would be happy with your limit amount, or if her response exceeds her ad, you may want to mention that. If she does anything other than agree to your limit with a smile, walk away without any further dialog. If she accepts with a smile give her your limit amount.

I've haggled a few times, both in the GG world and the TG world.

Usually, let's say about 85-95% of the time, it leads to a somewhat unsatisfying experience.

Actually, I can only think of one case where it came off well: the lady was a nice, tall, very well hung African American lady who hadn't listed a specific price, and what I had handy was about 80% of what she usually asks, and she said something like "Well, that's fair, how about 45 minutes?" and it went well.  I don't recall any other case where haggling led to a good experience.

From that conversation and a handful of others, I gather that a lot of guys delving into the TG world do some really egregious lowballing.  I mean she mentioned what struck me as utterly ridiculous offers, on the order of 20% of what was being asked.  I imagine that it's extremely aggravating and can contribute to a hostile attitude toward clients.

On the other hand, my absolute favorite local lady, who also doesn't list a specific price - when I first saw here, I offered what's a typical rate, we had a grand time, and she offered a lower price on subsequent visits - and the subsequent visits by and large have been getting better and better.  (And bi the way, she's LARGE where it well counts!)

Treat the ladies well, gents.  What goes 'round cums 'round!