This is the case in most shops that charge the NHJ in the shop fee but sometimes girls will sneakily ask for the $150 or $200 instead of the standard additional $100 to see if the punter pays it.
Happens regularly in shops like SBM and SGM, but the girls are younger and usually are all service queens so $145 shop fee and then $150-200 on top seems the norm in those kinds of shops.
But shops like 252 stanmore, 69 savann and 408 amora, majority of the girls account for the $50 tip in the shop fee when pricing extras in the room, of course you'll still get the odd few that try to ask for more, but as soon as you tell the owners or reception it usually doesn't continue.
Some girls like the south american girls tend to charge more, but the shop is aware and is the punters choice as a non asian ML/WL usually tend to charge more.