I rarely check profiles of regulars so I only ever bowl up with the historically accepted amount. If it's the same place as last time and her circumstances haven't changed (as a GFE regular one'd probably be a little dialed into what's up with her, surfing the EAS precipice and all
) then it should be the old money. If she points out the price rise and makes no offer to continue the existing arrangement then it's farewell from me. I don't see girls because they're just cheap, each is a VFM proposition compromising services, looks and attitude, if she disrupts that equilibrium then it's likely she's no longer an optimal choice and someone else will take her place.
I don't bother negotiating because everyone of them no matter how cheap is earning more per hour than I am.
The plus AND minus of a regular keeping you at your old rate is that you're both attached to each other. You may have other problems headed your way if you're not wary.
If you don't require a semblance of sincerity from your SPs then, much like a P&D, you don't require an "emotional" connection so the money question is just about are you willing to pay the extra to unload in familiar surroundings or better off finding new strange to satisfy your urges.