Id just try to avoid any seller that looks like they are not a collector and/or havent sold posters before (like check ebay feedback and see if theyve sold multiple posters) and if it looks like someone that may have just came across one poster and hasnt ever dealt with shipping Id talk to them before buying asking how they plan to ship it and offer the rule of "if you can squeeze the tube with one hand and it buckles its not strong enough" and gently remind them that if anything happens you will expect a full refund of purchase price and shipping costs .. that may prompt them to protect themselves a little more with a tougher tube and/or insurance .. Id say a lot of thee issues are just ignorant sellers .. they dont realize how rough shipping can be upon poster tubes .. and want to make as much money as possible so when they see the $1.99 tube at the post office they think thats great and cheap! Some are also disillusioned that once its shipped its not their problem. These are the people that need the gentile reminder that paypal will side with the buyer 99% of the time on lost/damaged merchandise.
I personally reuse a lot of tubes, just because I buy a lot so I have a ton of quality yazoo tubes just laying around and I only ship USPS priority with insurance! Shipping priority changes the way they travel and shortens the trip time so I speculate that there is less time for it to be damaged. That and once again speculate that they treat insured packages slightly different as well. The one downfall to my strict shipping is international can cost a lot !! I sent a poster to France priority and insured for like $130 and it cost me nearly $40 to ship. So shipping prices can be daunting and we just need to keep a watchful eye out for the inexperienced and help guide them to the correct path .. and if it is a poster worth having maybe offer a bit more money for shipping to ensure they sent it priority or buy a proper tube. Also if it will fit tell them to pick up a postal triangle tube and put the tube in that box to ship .. LOL .. make sure they know they still need a regular tube inside the triangle tube .. Ive gotten just a poster in that triangle box before .. the edge damage didnt make me too happy
So in short I think the only way to battle this is education and if its something we feel its worth buying then we need to take the time to try and help educate the seller if after that they still screw up then get your money back and send them the shittiest email possible !!