People really don't seem to understand the term "supply and demand." Simply put, when there are more buyers than there are of the thing they want to buy, prices rise.
Every seller, in a free market (which we supposedly have), naturally wants to sell for as high a price as possible. Every buyer, naturally, wants to buy for as low a price as possible. When these two natural forces are left to play out without interference, prices tend to stabilize. Think of an auction as a great illustration of a free market economy in action.
When the g'ment sent trillions of free dollars into the economy suddenly a lot of people were willing to pay more for things. Then, when the supply chain got disrupted (for a number of reasons), there were fewer goods on hand to sell. Both of these things combined to give us the crazy inflation we're stuck with now.
If any particular truck dealer were, in fact, scalping, everyone would shop at his competitor and he'd go out of business. When prices are high everywhere, it isn't scalping, and it isn't generally greed behind it.
-Speak