I've been doing this for a long time, so I have built enough courage to talk to some providers prior to starting. I have found that if they immediately start by askimg for the money, that's when I begin to negotiate. I've seen more expensive providers (300+) and they never seem to spoil the mood with money talk. So, I guess you get what you pay for.
The flowers at the locations on SAF are generally high volume, low cost. QV for 140 is a good starting point. If she's hot, maybe I opt for 30 minutes just to enjoy the view a bit more. And if she mentions GFE, I ask for details as some don't think BBBJ and DATY are part of a true GFE experience.
Lastly, I'm committing 200 for each visit, so that's the most I will pay these days. I have a couple MP's that usually have good flowers which never ask for the money upfront, so that's a good sign. But if I don't like the goods, I will cheap out and haggle, maybe even down to 120 if she's old. What's the worst that can happen?
Anyway, just my thoughts and approach for those just strating out. Happy hunting.