I have used the Condition Check request for Valve Purchases.
I negotiate as part of the sale, the Valves are to be tested when I receive them, and are then kept on returned dependent on the measurements taken.
If the Vendors measurements are close to ones taken on my behalf, I have honoured the Purchase, in some cases the measurements on my behalf have been much improved over the Vendors recorded values.
Having a assessment agreed as part if a sale agreement is one more step towards Caveat Emptor.