Is there any way you could institute some sort of superficial change in the checkout system (swap two form boxes, swap placement of submit/cancel buttons, etc...) prior to drops to disrupt the flippers using scripts/automation to acquire multiples? Or heck, just add a CAPTCHA challenge prior to checkout. I imagine the only people who would complain about the inconvenience are the flippers. I think most buyers/collectors would be happy to know that a unique human is buying each poster. It won't eliminate flippers by any means, but it would be a good start in restoring confidence...
We've actually considered CAPTCHA devices in the past, but we don't really want to add any additional computing tasks under our already heavy server load. As you know, for releases like Kill Bill, the pages load pretty slow, so adding a random image generator could only make that issue worse. Plus, we've never found any evidence of 'bots' being used through the checkout process. I'll admit, it's beyond my area of expertise, but I'm not even sure it would be possible - we create the product page literally the second before item goes live. Some people might be use monitoring programs to tip them off when the site changes, but there's not really much we can do to fight that.
The reality is that when we release a poster with a larger demand than supply, there's always going to be some people that try to capitalize on eBay. Our edition sizes are often decided on with the studios, filmmakers, artists, etc, so while some editions admittedly do not meet demand, it's not always our decision.
I'll admit some of our site operations are
less than perfect, but they're also the best we've been able to find for our specific needs. And we're always trying to improve. Which is why it's nice to hear ideas like these!