I would definitely set a strict return policy. I've not seen a FO supplier yet that even allows returns at all. You can't be sure what the person may have done to them, and they could be contaminated, which means you can't resell. If I sold FOs, there'd be no returns accepted. A lot of new candle makers seem to not realize how much time and research this business takes. You'll have to spend a lot of money if you want it done right, a lot of time, and there will be plenty of mistakes.