The origional arrangement would stand. What was agreed upon the date it was booked. It's different if it was postponed many times, or happened, and since prices rose, while scheduling a revisit.What should the industry norm be around cases where a date is arranged, say, 1-2 months in advance, and a deposit is paid but the SPs rates have increased non-insignificantly just prior to the meeting?
I can see reasonable arguments on both sides (“grandfathering” or fixing prices vs keeping them dynamic up to the point of the meeting). For example, an SP’s needs, overhead, and value proposition are not fixed, so their rates shouldn’t be either. At the same time, a date was agreed upon based on a rate that no longer applies and backing out could mean the loss of a deposit for the client. (Not an exhaustive list of arguments on either side, just getting the conversation going).
I picture it's like any business. The agreed upon price for the set encounter has already been set. Renegotiating the price only happens if there's a Renegotiating of the events that will happen within.