Losses on the sale of personal items are never tax deductible.
If this was a collection held for investment purposes (and if audited, you need to be able to prove this claim) then you report the loss on schedule D. You can deduct your losses up to the amount of your other capital gains, plus $3000. Additional losses are carried over to the future and can be deducted against other capital gains. Capital losses on schedule D have nothing to do with itemized deductions on Schedule A or the standard deduction.
