Price fixing is illegal, but only at the level where retailers conspire to
fix prices. The courts have repeatedly held that manufacturers can enforce
mandatory pricing levels on their customers (the retailers). Thus Garmin is
perfectly free to set a minimum retail price for its products and even
refuse to do business with retailers that violate the policy.

You already see it in almost every sector of the economy, but you don't
notice it because it really only works for scarce, high demand items like
the Garmin 296.