I'm in the reselling business and have a huge vintage Christmas collection from years ago. Now I resell some of those items but there is no COGS. Do I need to enter these items as inventory? And if so, what are the steps?

Recently I sold a vintage item for $183. This item was bought years ago for approx $50. How do I enter the $50 amount in QBs so I'm not showing a profit of $183? Thank you.