Mr. Corn -Kob : Blueprint cabinets are easy to find on the used market. Because ever since the advent and increasing-use of computers, all the contractors are increasingly going to digital these days. Oh sure, there may be hard-copy blueprints during an actual construction phase of a project, but.... once it comes down to "cold storage" , that is now being done digitally these days. So : Less and less need for cold storage of old blueprints.
Thus you can sometimes find good deals on these cabinet boxes. They often have superior roller glide wheels. And since 99% of our objects tend to be small and flat, most everything we find fits nicely in them . Good for shadow boxes, etc....
Here's an example of mine :