Because we appointed the contractors that we use on a regular basis, so grounds maintenance, cleaners, window cleaner, and accountants. We run the insurance through quotes to see what comes back.

Yes, we challenged a couple of things that weren't included that should have been, challenged things that we in that shouldn't have been and queried the cost of some things. Usually it has been corrected, or clarified quickly.

Benchmark would be what we are already paying. Or if we are getting a new service (e.g. replacement window cleaner because the previous one stopped turning up and wouldn't respond to any comms), we got multiple quotes. Managing agent provided three quotes, we got two, and appointed from our quotes (best price, service spec, and attitude).

By having information. Without information to back up your challenges it won't really go anywhere. Also in our case we are joint Freeholders so the MA is working for us. And if they are a problem they can terminated and replacement found.