Historically quite a few slaves were paid a modest wage, not all of course, but many. They often saved enough to buy their freedom when their "value" for physical labor was diminished by age. Many also learned a trade, such as blacksmithing, harness work, etc. and opened their own businesses as free men, similar to indentured servants who received passage, housing and an apprenticeship to come to the US. They typically worked 7 years before they earned their freedom. Black slaves didn't get this option. The first slave related court ruling was a black indentured servant "owner" who sued a lazy black servant who had not earned his passage, room and board, etc. The judge awarded the plaintiff ownership of the defendant in perpetuity.
