I just want to add an opinion here regarding one marble, the CAC Moonie - while it is often overlooked as a collectible, the blue Moonie that I have is one of the brightest, most attractive marbles in my collection. Granted I have a particular fondness for all things blue, but when you open the display box it just glows with an inner fire unlike anything else. No photo will ever do a Moonie justice, you have to see one in hand, and CACs are the just best ever made.
Were they more costly to make than a guinea? Probably. Did the kids of the 20’s think Moonies were the cat’s pajamas? Well, tastes do change, and I know my absolute favorite mib when I was a kid was a ruby red clearie shooter (worth about dirt then and today) and not the more colorful Marble Kings, Vitros or Master Glass. Beauty and cost are two different beasts, and kids only care about one of them.