Too expensive. Don't display your comics near the sunlight. That will avoid all of the trouble.
I agree that it's too expensive to incorporate UV protection in the plastic...would be great though.
I have three slabs displayed in a wall unit in my home office...it's nice to look at them as art pieces and not have to look for them if I want to check them out.
But, that comes with all kinds of concerns...UV fading, theft, etc. I'll probably put them away and rotate some books on display so fading won't be a concern.
The smartest thing to do is put them away in a safety deposit box...but I probably won't do that...I enjoy looking at them too much. It's bad enough I can't read the damn things!