There are actually a lot of collectible Busses, but do you want one that is rare or one that is just collectible. For example most of the Straight handled stuff is now fairly hard to get and collectible, however it is not especially rare(hard to get yes, rare no) What I mean is that there were a lot of straight handled pieces made, but now they are harder to find because they are in collections, in use, or in toolboxes
However, there are also a lot of rare collectible Busses. When I say rare I'm thinking one-off pieces, or maybe less than 10 pieces made. For example, how often have any of us seen a Bird & Trout come up for sale, or one of the Busse Axes, the 10" BB SH, etc. These are very rare collectible Busses.
Personally I have decided that I enjoy the "hunt" for rare collectibles, the limited pieces, the less than 10, the variants, the customs, the unusual pieces. They are harder to find, they are generally more expensive, but it sure is fun when you find something that you didn't even know existed
I hope this helps

