eBay has been terrible for some time. I offered to buy something about two years ago price at about $500 and the seller never wanted to negotiate a lower and didn't want to split the bundle, not even to sell me the lower value item, since they "know how rare the item is" and have just left it listed.
I tried buying an item for $30/Best Offer. Recent sales leave it at about $15. I offered $15, denied, $20, denied, $25, counter offered at $27. I let that offer expire on it's own. Best Offer for what?
As far as selling, I either sell here or trade in locally. I'm honestly trading some stuff locally more now than ever just to not spend lol.