SEAFARER ---Sorry to hear your past experience with a seller on
ebay . But this type of seller behavior has been around for the past 150 years and it is more common than you think .
There are many types of buyers and it sounds like he is fishing for the right buyer , YOU ARE THE WRONG BUYER .
Just to give you a explanation of one type who would buy what he is selling is the WA-LA buyer . This type of buyer only buys cheap mixture lots and packet material ,it is offensive for him to pay more than 50 cents a stamps . This poor souls needs some wow factor in his collection to show his wife and kids and impress friends who come over to his home .
So he goes on
ebay and see a Inselpost stamp that catalogs at $2200.00 selling for $17.00 which is high for a fake overprint. If you press him ,he would admit it could be a fake but hope against hope he thinks the seller doesn't know what he is doing but he has no interest to have it expertise . He digs deep and buys the $17.00 stamp and mounts it in his collection .
Next Christmas the family is over for dinner ,so he pulls out his collection to show his family what a serious collector he is and a expert on stamps . Then WA-LA shows everybody his $2200.00 stamp and a catalog page showing $2200.00 he now feels like a serious collector who has a valuable collection .