I found something the other day I've never seen, but which I thought was an ingenuous idea: little bottles of bitters. For sale for $3.99 for a 100ml bottle were "Bitter Truth" bitters. There were five different kinds, or you could buy all five together in a box for $20 or so.
As soon as I saw them I realized that I thought that the usual bottles of bitters I see were much too large for me, and I was happy to be able to buy in smaller quantities, especially different varieties of bitters. The two varieties I bought were "Creole Bitters" and "Jerry' Thomas Own."
In looking morel closely at these bottles, I see they say, "Not for Individual Resale", so apparently the retailer wasn't supposed to break them out of their 5-bottle gift pack. But I am so glad they did.