The IRS defines a business, in part, as an ongoing activity with the purpose of making a profit. Clearly, you can’t make a profit when your cost basis equals your income from your sale. Therefore you are not really a business. The bright side is that you received the goods for free and you derive tax free income from the sales. I would hope your storage and other expenses are not greater than your income from your sales. If so, you just should have donated the items you didn’t want to keep.
