There is a hardwood dealer nearby that usually has a few factory-second white oak cutting boards that can be recycled to make other items. I've also found some hard maple cutting boards in an end-of-season clearance sale in a gift shop in a resort area. In either case, I got great timber at a very good price.
The one thing to worry about is whether the original item had been finished - often, treenware is finished using a 'food safe' mineral-oil/beeswax combination that could be incompatible with whatever finish you might want to use on the item you create using that wood. It's ok as long as you turn away enough of the surface to get past the finish - and fortunately, those 'food-safe' finishes don't penetrate all that deeply into the wood.
There is a turner who had a You-Tube channel who specialized in items made using recycled wood. As I recall, most of the wood he used came from hardwood furniture that was being thrown away and that he retrieved from the side of the road on garbage day.