I can definitely see why people would pay more for VHS big boxes in great condition, but I think well worn/sun faded copies add to the charm of collecting the tapes. Not that I collect them, but when I think of the era, I recall moderately beaten up covers and worn tapes. That brings back memories for me. I don't care how people spend their dough, but buying VHS when titles are on DVD cheaper and great art scans are available online is absurd to me.
I never got into the rarity and collector bullshit in movies or video games, though. I guess it gets some people off that a handful of others would be jealous of their Zombie Wizard VHS that gives them no pleasure their DVD couldn't surpass. Different strokes for different folks, but we all know most people bidding huge bucks on Ebay for dumb shit they have really no personal ties to is just some goof showing off how big his nerd cock is compared to others'.
I will freely admit I buy way more than my share of dumb shit, too. Pot's just callin' the kettle black. In my case, the stuff I have isn't bought for rarity but for either quality, my interest in the subject matter, or uniqueness. I just don't see anything gratifying about blowing $1800 to look at boxes in person I can see images of for free online. Let's be honest, unfortunately no one is paying those bucks for the films themselves. And if that's the case, what's the point in owning the box art?