Supposed there was this big coin show coming up and you can’t go but are looking for someone to buy coins how would you find such a person and what do they charge?
Hopefully, the dealer/agent is someone that you have had successful transactions with in the past and s/he is going to the show. You provide grade/price range, tone, etc.
If it is the first time then I would start small $-wise until you are sure the the dealer/agent is in sync with your desires to prevent the heartburn/sour stomach feelings.
The dealer I have been with makes a lists of items I am interested in and brings them back. I have bought 99.9% of everything brought back. The 0.1 was because he wrote someone else’s coin on the list for me. No extra charge since the dealer was already attending.
An economist is an expert who will know tomorrow why the things he predicted yesterday didn’t happen today.
If the ANA is coming to town (or other big national show) it may be worth having an agent, especially if you are in the market for a Stella, a 1794 dollar, or a 54-S QE.
For a typical local/regional show, you are probably fortunate that you are unavailable. There is a high degree of certainty that you would not find anything you could not find better and or less expensive online.