I have found plenty of 40% Silver Kennedy Half Dollars while coin roll hunting. I am debating on trading them in for 90%. If I do this with a dealer/coin shop then then will buy at spot and sell 90% at a premium. Or I could sell my 40% at a premium and then buy from the dealers. What do y'all recommend? Or should I just keep my 40% since I basically got each coin for 50 cent front the bank.