As Steve said it is pretty popular to take chips that don't have the "nicest" inlays or solid roulette chips for example. They'll get them milled and re-label them as different casino chips so that is why you want to be sure of what you are buying before you do, unless you know that it is what you want.

Very popular for those that are creating sets and they want some chips that have nice edge spots or an edge spot progression.