I concur with everyone here, I have gotten a few cards from ebay sellers, some of whom have shipped in used and recycled PWEs! Now THAT is scraping the bottom of the barrel! Even with a card saver, you are still not guaranteed that your card will not get bent or damaged in the mail. I usually use cardboard or the cut off bottom of a folder in addition to a card saver or toploader when mailing, and go non-machinable for goodness sake!
I had some autographs I sold get lost in the mail one time about 15 years ago, and ebay ruled against me so I was out the money, unfortunately. I learned a tough lesson from that, and have always charged 5.99 shipping or more depending on the item (signed baseball, more like 10.99), but use that to mail in a bubble mailer with tracking or an 8x10 in a standard envelope with 2 pieces of cardboard, so it gets charged as a package rather than standard envelope weight. Still, its worth it when you are dealing with people you dont know on ebay, and ALSO dealing with USPS.
Typically on here if I am sending out a freebie, I do 3 stamps on a 9x13 envelope with cardboard since its a giveaway (if it arrives damaged, I will give you another photo!!). But if someone paid me for an item, I try to do my best with shipping, unless we agreed upon PWE being ok (and even then, I make sure to package safely, not knowing how rough the trip might be in the mail!!)
I get it, the card and memorabilia market is hot right now, which is great, but if sellers want to make a go of it, they need to realize that they are not going to be doing any business if they lose money on transactions they have to refund due to items arriving damaged!
this has to be at least the Fifth one. 
