I know this might sound stupid, but what’s your process? Say I buy a transformer for $10 and sell it for $20. The shipping is $10. So I get paid $30. eBay and PayPal feed kick in and I probably end up with $15 bucks back to myself after I ship it. so am I being taxed on $15 or $30? Is this a case where the government doesn’t know about the eBay and PayPal fees and shipping costs? do you screenshot the purchase for evidence you paid $10 originally?