I don't know the legalities behind backing up software, but even if you have two copies, you can only use one. If one of those copies end's up on a friends computer, then it's technically theft, right?

If you buy a zombie bust from me and copy it, not only don't I have quality control over the copy, potentially hurting my brand, but I was robbed of the second sale. Not saying you would or are an evil villain, but a big part of the expense of resin is the molding, so I doubt anyone would only run one copy and destroy the mold. So maybe a couple, not to sell, but to have for practice, maybe hook up a friend. Then that friend paints his and puts it in a show, where a couple a hundred people look at it a see a crappy copy full of patch work and judge my product based on something I have no control of.