I would say, if you like them, try to cherry pick them. My favorite game was try to find one fully struck. Not as easy as you would think. Many times I would try to do this at a regional show, even after I stopped collecting them actively, and more times than not I would leave the show without a purchase. They simply were not struck really well due to a design error, and getting one fully struck up will take quite a bit of work usually. Of course Overton and others have a whole other level of cherrypicking, but I am just talking picking out full strike examples. A person can spend their entire collecting career on these, and still be learning something the whole time.
scarce: insufficient to satisfy the need or demand; not abundant 30k slabbed or TPG coins is not scarce by most definitions, especially if you count the unslabbed/ungraded ones. You can easily find these for sale in about any local dealer shop and easily online for sale. That does not mean they are scarce or rare. Scarce to me would be 1 out of every 10 dealers (or more) *might* have one (literally just 1) for sale in AU or better condition.
Actually the banks used the capped bust halves because they stopped making dollars in 1804. There were no dollars for the banks to use. During the bank holiday of 1933, some of the banks were found to still be holding stocks of capped bust halves as part of their cash reserves.