"Nothing is the same as it used to be..."

*Begin rant*
This guy walks in and says he has a box of books in the car and wants to bring them in. I say "Sure, but we only offer store credit, is that okay?" (This is a conversation we have with every single customer that brings books to us). ?He then scrunches up his face like a 5 year old about to throw a temper tantrum and replies in a mocking little high pitched voice, "Only store credit." (WTH) He then marches out to his car and returns with his box of books. While hes out there, I tell Emma I'm done dealing with this guy already and it's all her from now on because I don't do well with assholes and I don't want to lose my job sooo....He comes back in, Emma verifies hes okay with store credit and he wanders off into the back somewhere. Well, none of the books he brought in were from this century and they must have been sitting somewhere really nasty and gross for at least a couple years, (which is also normal for people to bring this stuff to us, like we would actually be able to resell it to someone). Emma and I pick through them and pull out 4 or 5 that Emma starts checking for value. He comes up and starts pestering Emma..."So all the books you cant take are in the box? Wow, I thought you would take more...why cant you take them...." Emma explains to him they are old and gross (in a nice customer service type way). He says "so you cant take ANY of them, why not any of them, PRINCESS??" and she says "Well it looks like we can only take this one." He replies "So what, I get 50 cents for it? 75 cents?" (I'm about to turn around and tell this guy he can get out and not come back EVER, please) She says "We can give you 3.50 for it. If you're looking to just get rid of them there's a goodwill just down the street." To which he says, in his asshole voice "There's a dumpster down the street." and then "I just thought I would get more for them. Nothing is the same as it used to be..." (Yes, kind lovely pleasant sir, nothing is the same, because if it were, you would most likely be a decent human being instead of a grumpy selfish old fool thinking you can walk all over people and they will in some way be compelled to treat you humanely back). So he then took his store credit and left. Thank God, and please don't come back. Sadly, a large portion of customers are like this, not only at our store, but at every store, because I've seen things like this happen in other stores as well and you just have to think, how on Earth do you live with yourself treating people like poop every day?? (Side note-I generally try to censor myself when writing publicly, hence the use of "poop"). I have this theory that some people live every day trying to ruin other people's days. I came up with this because I can not imagine that people are really as rude and mean and terrible as they seem unless they are genuinely trying to be a very LARGE female dog or donkey. So to the people out there that are like this, and have to turn every single thing into a huge ordeal because its ALL ABOUT YOU or whatever,  please grow up, get over yourself, and for the sake of the rest of the world, fine a rock, get under it, and don't come back out ever. K, thx, bye.
*End rant*