I remember some dude a few inches from my facing nearly screaming that his baseball card was worth $750 and my offer was beyond insulting it was criminal! LOL.
Rule number one when it comes to buying and selling for a profit: Your shit is only worth what the market is willing to pay for it on any given day. Period. End of story. I offered him 50 dollars and I’ll tell you why later.
There are several ways to educate yourself about the worth or lack...