I'm a special case
I get back-up copies but with my gimlet eye I often find differences in printing, a slight lightness in colour, not saturated enough and it bothers me. I had a couple of Vieville back ups, same publisher, same edition, but they were too light for me compared to my first copy so I got rid of them because I knew I'd never learn to like them quite as much.
I have had this experience a few times. I have four FX Schmid Cosmic Tarot decks an (again) one is too light compared to the others - so I don't like it. Then a Morgan Greer, printed in Italy has a couple of out of focus cards so (again) it spoils things rather.
But all being well - assuming I am satisfied with the second or third or fourth copy - then I keep them safe and untouched. I couldn't possibly use one at home, one at work, one in the kitchen, one wherever. They are kept *box fresh.*
So when I get another copy of a deck, I compare it very closely with the one I love. I'm thinking of getting another copy of the Japaridze because I love it so much and if it goes into a 2nd printing that's often when differences creep in. I like the edition currently available and would hate it to be different. However, I have to add that I find LoS decks the most consistent of all the tarot publishers - I have never noticed differences in colouring between editions.
It's always a risk.