I've never purposely backed up anything.
Like a lot of the others here, I have a hard enough time using up one product, muchless two or more!
And I'm sure by the time I get through one, I'd want to move onto something else (unless it's HG status of course!). I do have multiples of some items, but it was because I already had the single, then it came in a palette or set.
Backups are so pointless for me. I'm amazed by people that can use things up!