Looking at recent sales, slabbed MS65 coins like these (Kennedy '76-D/\71-D) are likely to sell for less than the cost of grading. Even MS66 will be borderline IMHO. You could try to sell them individually for a few bucks each, but for me the juice isn't worth the squeeze. Maybe try to sell by the roll. It appears BU rolls of 20 coins go for $19-$29.