Real bones are rare and highly valuable, there is a market for that, with very high figures for well-preserved skeletons of "glamorous" species like t-rex and other large dinos:
List of dinosaur specimens sold at auction - Wikipedia
en.wikipedia.org
You can't mechanically reproduce bones, let alone ancient dinosaur bones, they have a complex granular lattice structure. Fake bones would be easy to spot. I suppose you could pass real individual bones from mammouth (which aren't that rare) or large mammals for dinosaurs, but those wouldn't pass a basic inspection from an expert.
You know that something like 90% of the bones on display in natural history museums across the world are replicas right ?
You also know that a genuine fully intact skeletal structure of a dinosaur has been found for almost none of the creatures they claim existed.
It's usually something like less than 30% of the skeletal structure, with enormous gaps.