Never had a real problem with this aspect regarding around 650 or so machines.
It is part of the requirements and steps of the process when confirming sales.
If an owner is not willing to discuss on the endstate via telephone, a buyer adds unnecessary risk, similar to absence of game inspections. Set up of sale, may not be immediate via phone, and it is perfectly acceptable via text and email, just like questions or photos. People are busy, and texting is simpler.
I have negotiated sales by nearly every popular social mediums (today and past), and traditional methods methods at some point or another, since they all have value.
If a person remains shy about communication, just walk away, and let the problem be someone else's issue, normally there are some specific reasons.
If a person is getting worn out on the "big game hunt", it might be a good time to take a break to avoid burnout.