Here's a list belonging to the top ten Pitfalls that catch out beginner Marketers (and many established ones too!).
Honest companies will usually buy back any products an individual fail to sell. Yet, you get to claim (or deduct by the G.S.T. collected by you) all the "input tax credits" (G.S.T. https://optimiserenergy.com/forums/users/elveramartens21/