Should I be closing shops?

On the other hand if you don't do a rollback, and just remove the duped items, people lose money, items they may have bought (though in SOME cases this is their own fault for buying things that are obviously duped) etc

Plus, as [MENTION=2622]moore4me[/MENTION] already mentioned, it leaves a lasting impression to the playerbase basically telling them to go ahead and take advantage of these exploits and use the scrolls on gear since the gear will, more often than not, not be deleted.
People who have been around long enough know that does tend to be the case most of time.