I didn't say a client was not involved in determining how much they want to pay for a mystery shopping program in total. I don't believe they are involved with each line item of the program with the possible exception of the shopper reimbursement since no restaurant is going to consider reimbursing a shopper enough to bring a dozen guests. There are many more factors than just the shopper fee to consider. Bids for programs will include editing, scheduling and IT along with all the other miscellaneous business expenses and some profit for the mystery shopping company.
Using my favorite example of the plumbing company, does any you have hired give you a breakdown of charges beyond labor, materials and a trip charge. Nowhere in the estimate do they break it down further to tell you how much of the labor/trip charge goes to salaries, equipment, gas, rent, etc., etc.
Equal rights for others does not mean fewer rights for you. It's not pie.
"I prefer someone who burns the flag and then wraps themselves up in the Constitution over someone who burns the Constitution and then wraps themselves up in the flag." -Molly Ivins
Never try to teach a pig to sing. It's a waste of your time and it really annoys the pig.