Knocking on the endpoint…
We ask it what it charges, read its catalogue entry, apply the policy, and then ask it again to see whether the price held. That is two round trips to somebody else’s server, so a few seconds is normal and a slow answer is a fact about them rather than about this page.
Walks a whole purchase in the order a buyer asks the questions, stopping at the first that objects. Nothing is signed and nothing is spent. The payment check asks the narrower question, about a payment you have already decided on.
Over the endpoints WE have knocked on, which is our reach and not the catalogue. A disagreement is between two statements by the SAME party, their listing and their endpoint, so it is theirs to explain and never ours to resolve; it is not evidence of fraud and a seller may simply have moved their payee and not relisted. `comparable` is the denominator: an endpoint that names no payee, or whose listing names none, cannot disagree and is not counted either way.
Which endpoints, and whose, needs a plan. Any single endpoint you name is free: search for it above and its own reading is on the row.
The rehearsal could not be run. That is not the same as it saying no: nothing here objected, and nothing here was established either.