In the old days, it was a lot less likely to have a npb, but now every idiot is just browsing the site on their smartphone and see ebay as like a store where they can change their mind or return within 28 days. It's ebay's fault in a way for going more commercial and having more big companies have platforms there. But it's not great for the small sellers.
I haven't sold on ebay in years now because it is no longer the place for small sellers to sell collectables :/
I have a box of pony doubles that has been sitting under my chair for the last 2 and a half years...