Why is it that greed for gold brings out the worst in human...

Why is it that greed for gold brings out the worst in human nature. I recall a Salvo's Op-Shop, received a donation, the wife had left the husband, gave him back all the jewelry, and the broken hearted husband gave it all to Salvo's, and the word got out, of a special SALE. I turned up, and in the line-up before opening, all the cheery regular customers had turned into werewolves. The doors swung open and it was a stampede, with little old ladies getting trampled. A few laps, before they'd realized it was all behind the counter, and everyone took up a position. The store manager tried to keep things civilized. But there was pushing and shoving. Squabbing. Like crazed villagers, with pitch-forks and sickles. I stood back as one clucky duck snatched an $8000 rose gold necklace from under my pointing finger. Well over $150,000 of jewelry was gone within minutes. I had next to none of it. I was shocked by the ferocity of it all. A bit later i was at my car, i owed my housemate $500 she'd lent me, for the sale, and i hadn't got real value for my money. Designer rings, little candy stones and not much gold. I went back, and suggested an exchange, and The Manager's eyes lit up. Yes Sir, and she'd held a tray in reserve and we made a trade, and it was very profitable for me, in the end. I'd managed to maintain my dignity, hadn't been ripped off, and even did alright. It could have been better. It could have been worse. In the end, it was ok.