Yeah, this is an expensive thing to do... I am one of those people.

I have 3 pair of the same shoe in different colors.

I also have the same things in my bug-out-bag as I do in my camping, or vehicle kits. Eventually a BOB won't be necessary as I duplicate the gear all over!! LOL

I have learned to buy one test, and then by more... too many times I have ordered multiple from the get-go and learned later it was wrong and ended up with multiples.