I am in PA also and have Erie insurance. I don't remember the specifics of the conversation years ago, but my pins are covered under my homeowners insurance. I also have them covered with an additional rider policy that includes my wife's jewelry, my watches and both of our vintage toy collections. Oddly enough, if our house burned down, the house itself would be one of the easiest things to replace.
I don't quite understand your agents definition of buy/sell/trade as a business. Don't all collectors do that in one form or another?