In 2023 we sold large stamp and coin collections inherited more than 30 years ago from our fathers through a recommended auction house (they do not provide a 1099). We received a check for the sale, less their fees, which we deposited. We know this is taxable, but we have no way determining a cost basis for comparison to the sale income to obtain the resulting gain/loss. Any suggestions of how to report this on our taxes or do we just have to take it as a capital gain?
