Mel is right, anytime there is a problem in the chip world, the dealers get the blame. I know dealers that pay premiums to get chips, to service their lists. Sometimes to other dealers and sometimes to chippers that call themselves traders.
There are also many Las Vegas chippers that get 5, 10, or more of each chip, to trade face for face with trading partners. I personally get between 2 and 4 of each chip to trade with partners in other gaming areas. The amount I get depends on which partners want certain chips.
A dealer servicing a list, sometimes has to work very hard to get what he needs.