Mutual trust between seller and buyer is precious.
Last year a dealer that I know loaned me his personal collection
of Barber "V" nickels. I compared them with my set. The next day
I returned it and bought three of them.
Another seller was willing to wait until I could send him a small personal check for the balance
due on a coin. "Collectors are much better at paying promptly than dealers."
What a compliment! (I left that show with the coin.)
There is one bit of advice that I follow:
"Treat the dealer as though his time is as valuable as your own."
Be it in an shop or at a show, this advice has served me well.
A CCF member sent me a coin before I paid for it!
To be sure, this level of mutual trust and respect takes time to evolve,
but the payoff is worth the effort.
Dealers come with all different kinds of personalities.
Do not get discouraged.
And walk away if you feel it necessary to do so.