Anyways at whatever point you need to do this, check that you do a true blue research and expand some capability in it from the people who have their dynamic in this field.
The American eagle reserve is one such center where buying and selling of coins are done. They take the pride in the service and the products that they offer.
Today the trend might have changed and they are no more used as currency but their value has increased with passing years, people have realized their importance and that is why they have captured the market.