"What about a lady who charges 500/hr but offers big discount on multiple hours?"
Well, to some extent that's what we're talking about ( i.e. "what qualifies?" ), but my opinion is that once someone is 'over the bar' for the first hour, then they are "in" regardless of what discounts are offered after that. For example, if someone only offered 12 hours dates ( and I mean "for real" not some BS where they said that on some website, but IRL were giing out $20 BJ's behind the 7-11 ) for $1,500, then I'd say that's in also, even though the division would show an hourly rate of $125.
"What about a girl like Dakota who charges about $1000 per session but can be seen at Julie's for $250? "
I think it's fairly clear that Dakota's offering at Julie's is not "high end", so perhaps that's a poor example. I'd also be curious how much work she did that was "high end". Although I do think that discussions of "alleged high end girls which actually work for much less at mainstream places" would be fair game.
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In actuality, I think it's fairly easy to tell if someone falls into this category, regardless of what number you're looking at, if you just think about it a little ( hell, one way to know is "Has this person been talked about at all on the board, and if at all, has anyone said 'no one is worth that price' ", and then use that as a guideline).