Rarer is a material or design, the more it is worth.
But this is perceived scarcity... stories can be manipulated, so scarcity can amped up to increase prices. Scarcity can be manufactured, like in a stadium where the stadium's owner owns the stands and doesn't allow food from outside.
Alternatively, scarcity is as much resource distribution as availability
These strategies goes against the principles of a free market. Free market are supposed to optimize price