A sales technique which has worked well for postage stamps is that of
The way this works is that as a buyer, you are not sure you want the item.
So you ask the dealer to send the item to you before you make payment.
That way you can inspect the item before making a decision.
If you have a feedback on eBay of 100 or more, or belong to a philatelic
organization, I will be happy to send an item or two to you on approval.
If you like the item, make the payment.
If you do not like the item, all I ask is that
you pay the return postage for the item.