It also depends upon the chemical supplier and the service contract that you have signed with them.
Some large reputable companies charge more for the same or similar chemicals, but they also supply a lot of service as well, like monthly monitoring/titration of the chemical concentration, both detergents and sanitizers. This is very nice to both keep your sanitation SOP consistent and your sanitation crew stable and happy with the performance of the chemicals. QA will still need to check sanitizer concentration daily, and also periodically validate the detergent concentrations in-house through titrations, but much less often. You can often call upon the Rep to come out and retest if you think your usage levels have changed.
Some more budget chemical supply companies do the bare minimum, basically dropping off the chemicals and maybe monitoring usage. The cost much less, but your QA and/or Sanitation department then needs to do the testing/monitoring and validation, and they will need the related testing kits and the training to properly use them.
So management will have accept paying for it is some way, either the service or the equipment and training to do it in-house. One of the biggest tools I had was the SSOP that was written by me but approved by management. What they had approved in writing, we had to show proof that we carried it out to the auditors satisfaction. If management wanted to change it, I had to rewrite it and get it reapproved by management on a procedure change form. That way I had it in writing no matter what.
If the auditor suggested a change, I might review your Risk Assessment program in that area to see if you are missing a possible hazard.