Under the old IRS definitions, for an expensive hobby like magic cards you could just consider that your lifetime year-to-year costs of participating in the hobby on average offset whatever you made from the hobby. As long as you didn't operate an actual business like a physical or digital storefront, the IRS would just consider it all hobby income. That changed after 2017.In your scenario, it's still as you say side money and making a profit. My example would be Bought a gun for 1k new, sell it for 700 later, upgraded a telescope, sold old one.
Vs, I can understand say i have my salt tank. I continuously grow and clip coal for sale is certainly side money profit even if it doesn't cover the costs of my aquarium.
Or just rabble rabble taxation is theft, become ungovernable.