My father had a first year duck stamp and I used to collect stamps. I still buy collections but mainly to get uncancelled stamps to put on envelopes. But when I look at buying a collection, I always check for duck stamps since they all seem to have considerable value and thus make the collection have more value. Many very old regular stamps are worth $1 each but who wants to scan one, make up a description, sell and mail a stamp for a buck? Too much work for this lazy old guy so I just put them an envelope. I have put 110 year old stamps on envelopes containing chips I am shipping.