1959 thru 1964 Mint Sets Availability?

Many years ago, I was accumulating 1959 thru 1964 Mint Sets. They seemed to be relatively available for reasonable prices back then. I always looked for original sets that were in nice original envelopes (along with the cardboard and slip of paper).
In recent years, I noticed that I rarely see these mint sets offered on the BST or coins shops.
On the other hand, the 1959 to 1964 Proof Sets seem to still be readily available.
Has there been a big drop in availability of these original 1959 - 1964 mint sets?
This is just an observation. I am not interested in paying the current prices for these mint sets. I still have my nice accumulation of these sets obtained years ago.
So, is it my imagination, or has the originally packaged 1959 thru 1964 Mint Sets become much scarcer over the years?
Comments
I think Mint sets of that era have always been much scarcer that the proof sets. I do remember looking thru tons of the '63 Mint sets looking for the DDO-001 quarter, tho. These days the Mint sets are much scarcer. I'd be willing to bet that many were sacrificed to the various silver melts during the last 40+ years.
The Mint sets are scarcer than the proof sets. As @koynekwest said, that always seemed to have been the case in my memory.
Proof sets were the rage back at the time. Mint sets were considered to be a way to get Unc. examples for your coin albums.
Occasionally, at gun shows here, there is a table or two with coins as well. I am always on the lookout for 64 proof sets, for the AH Kennedy variety. Have found a few over the years. Cheers, RickO
Keep in mind that every time one gets broken up to sell individually, that's one less from the sales total. At some point in time they'll be even scarcer. And while they are still relatively easy to locate, the prices are reflective. Supply and demand.
These sets are much less available than only a few years ago. I'm seeing bigger and bigger premiums for them especially at retail. But retailers rarely seem to run out of them, too.