Losses on personal items are not deductible. Each gain or loss from a personal item sale needs to be reported separately. If you had a loss on the sale of any personal item, it can't cancel out any gain on the sale of another personal item.
Example: Tyrone bought a couch for $400 and sold it two years later for $200. Since he sold it for less than his original purchase price, the loss can't offset other income, and the sale would be reported as $0 on his tax return. However, when Tyrone bought a table for $200 and sold it for $300 two years later, he had to report the $100 gain as taxable income.
How do I enter a 1099-K for personal item sales?