I read this post today, and shared this as a comment. I felt that my thoughts were ones I also wanted to share here (because really, are you going to search over 350 comments to find mine??!) so here goes.
The women of my family have always had button bins. My mom had one that I used to love to look through when I was younger. Then I went to college and didn’t do much sewing or crafting, and didn’t have a button bin. But I saved the extra buttons that would come with the clothes I would buy, or when a sweater was gifted and lost a button, I would cut off the rest to save and replace them. When I got into sewing and knitting, I would go to see my grandmother, who has a drawer in a file cabinet full of buttons. I love looking through buttons for many of the same reasons you do. I have started a button collection of my own, but it is still fairly small. I look at collections of buttons on ebay sometimes, dreaming of how they they feel or what treasures I would find in them. I have not purchased any because I would rather the buttons find me that I like over time, instead of pursuing them and be disappointed that the buttons I got were impostors somehow, not truly to be added to my button bin. (I have some reservations about buying in online auctions. It seems to cheapen the experience somehow.) Anyway, my dreams of a button box to match the collection your grandmothers have passed down will be fulfilled some day, I just know it!