Standard price is 75k for foreigner, 65k for Japanese.
10k discount usually for new girls or some campaign going on (Japanese pay 55k only), and they usually don't give to foreigner cause i asked MIB before.
i think you are lucky to have the discount, they should be giving to you seeing you as their first time customer.
side note, typo error , is MIB and not MIW above.
MIW is a party wearing white uniform , haha.(if you know)