I think Ts are allowed to ask for what they need- raise fee to all clients or keep the old ones on the same rate... However, both times it should be discuss beforehand - preferably in the beginning of therapy so the client can freely decide (after some time you already invested a lot into the RS- not only moneywise- and are not really free to just stand up and leave).
My T is a bit awkward re the payment (got the feeling he doesn't like to take money from his clients- weird I know)- his clients are kept at the same rate (thank god). Having said that, he's not nearly as bad as your T. WTF? Don't have to pay, just telling you that you should? Would not go well with me. Perfect time to practice standing up for yourself- not saying not to pay (I would) but tell him how hurtful his approach was. Fr what it's worth, I don't think he's trying to get rid of you...