Concerning items sold on eBay, yes, you will have to pay taxes on profits. However, you only pay taxes on your profits, not on all items sold. Another thing is that you can deduct expenses too. Regular expenses for eBay include listing costs, shipping and insurance charges, PayPal fees, etc.... If you are selling old items you may not actually have profit. Selling an old baseball bat for $15 when the bat was $45 new is not a profit. Check with a lawyer in your locale to discuss more of the details.