I do not lie the folding coin albums. They can cause silver to tarnish because of acids in the paper. I use vinyl pages that hold 2x2 flips and those books with the sliding covers.
a blue coin albums will ruin a coin... and you do not see it until you remove it from the album sometimes..
IMO, "the whole income thing" is a lot easier to work with than US paper currency straps vs. coinage. Coins are just harder to transport.
But, keys are only key if you assume collectors wish to collect the entire set. Absent that, they are simply scarcer issues but not worth nearly the price of what is being asked. This is clearly illustrated in 19th century coinage. Look at SL halves in the 1880's. IF collectors were collecting the entire set, these coins should be value 100X the price of a 1916d mercury dime. Since there is almost no collectors doing that, these coins, even though a couple of hundred times rarer than a 16d, are across the board worth less.