I would think it depends on how particular you are and how much this display matters to you.
I'm an extremely particular guy. Whenever I buy something as complex as an electronic component, I'm always wondering "is it functioning the way it is supposed to?" It's just a fact of today's marketplace that everything electronic you buy has aspects that don't work the way they ought to, whether because of a bug in the software or just bad design. So I find there's always something where I have to worry "Is the way mine working typical of the model or is it something particular to this one device?"
Buying something open box just makes that worry more intense for me, so it isn't worth the money I would save. If it's the sort of thing were you're just going to turn it on and be happy with whatever it does, then open box can save some money. I'm not that sort of guy.