I think you badgered her a little bit when all she wanted was to cancel. Why argue about it? Life’s too short, personally I wouldn’t have wasted my time or energy.
And for the record, a high price is NOT a rip off. If you quote a price for a service, and the customer accepts the price, and you deliver the service promised, then nobody has been ripped off.
If you’re managing to get good prices for your service, that is to be commended not criticised. The only ones who need criticism are the cheap brigade who work for beer money.