The sofa required legs of course, which were an additional $20. No problem, because $40 is below the manufacturing cost. Also, the sofa requires a cover, which costs $250. And I needed to transport it. And pay interest to the credit card company. So I only paid $350 for a $300 sofa.
Giving away your art for free is a stupid idea. But selling it for an alluring price, with necessary but expensive add-ons, can sometimes be a good strategy.