Well I think a bit of steady on is needed here.Same for me...surprised at this turn of events as TBC has always been priced about right.
Without knowing who, in a private message, gave those extras rates to sparky, none of us here cannot assume all the TBC ladies are expecting to charge clients those rates. However, such extras and the prices for them are really the discretion of the lady offering them. If she wants to charge more then there is a risk she will lose out.
If you are worried or not happy perhaps talking to Vivian might be a good course of action. If perhaps she has set establishment guidelines for extras, then she needs to be informed directly.
Personally, I prefer to ask the lady of choice in the establishment at the time rather than in a private chat conversation.