No they did not fall off a truck.
What happens is that an authorized dealer buys more units than they can sell in order to qualify for a quantity discount. They then resell the excess units to "grey market" dealers like NewEgg at or near the discounted wholesale price they got from the manufacturer. Since the grey market retailers have no price-fixing contracts with the manufacturer, they are able to sell at prices barely over their own cost.
The blame almost always lies with the manufacturer, the people who process wholesale orders know their customers. They know when an authorized dealer is buying more stock than they can move, but they let them do it anyway because the manufacturer's own internal incentives reward them for selling as many units as possible. Some manufacturers, like Denon, are real arseholes about it, they will deny warranty coverage if you buy from a grey market retailer. That puts the onus on the customer to enforce the rules that the manufacturer themselves are too sloppy follow.
I'll go out of my way to buy a grey-market unit when the manufacturer uses customer-hostile tricks like denying warranty coverage in order to fix prices. Turn about is always fair play. Factor in the cost of a third party warranty from a company like Square Trade and you still save money compared to paying the "authorized price."