My experience why I sometimes believe buyers are at fault:
My selling of WP's is rare. This is a hobby to me and not a way to make money but this series has struck me differently so I wanted to recover some of my money. This past weekend (F-Su) I listed 20, twenty auctions dealing with the 50th Series. 20 occurred because (between 1 gravity feed and 2 BB's) I was able to make 2 of each sub set. Each auction showed exactly which cards were included and described what you received (9 cards from X sub set) and what they were. One guy bids on and wins 8 of the first 10 auctions I listed. He paid and I shipped and then he realized he blundered and contacted me yesterday. This is where it gets amusing. He tells me he isn't happy with his purchase and doesn't necessarily blame me for his mistake but he somehow thought these sets (Politics, celebs, etc..,) were all chase cards and he goes on with his lament about how he grossly over-paid. To that he did. He paid $50.00 for eight of the sub sets in the base set when he could have purchased an entire 90 card base set online for $10-$20. He then goes as far as questioning how and why I listed my auctions as I did and I explain to him that not everyone might want the entire 10 sub sets and some might want to pick and choose. Essentially, these auctions were not focused on someone like him. In his haste and assumption he fudged up and wants to share the blame with me.
Some buyers are frustrating beyond belief.