This is a classic case of high demand and low supply. When more people want a product than there are items available, the price naturally increases. This is because buyers compete, and sellers can charge more since their product is scarce.
Think of concert tickets or limited edition sneakers - when they're in short supply, people are willing to pay extra. This creates what's called a "seller's market." It's a key principle in economics that shows how scarcity influences value.