Advance money received reduces the cost of a capital asset unless already included as taxable income in a prior year. Advance payments received during negotiations for transfer of a capital asset are deductible from the asset's cost of acquisition, written down value, or fair market value when computing cost of acquisition; however, if such an advance was previously included in the taxpayer's total income under the income-inclusion provisions for advances, it must not be deducted from the asset's cost or value.