It's really not tough, you take whatever the gross amount is and you subtract the costs of selling (actual shipping, packaging materials, Paypal and Ebay commissions and the cost of the goods originally) and whatever is left you report on your individual income tax form as income. Be sure to have receipts for the shipping and packaging materials in case of an audit. You can print various reports on Ebay to show what commissions you paid last year. You then pay taxes at your individual rate on this income.