to stock-based compensation, $788,000 related to payroll and payroll related expenses, $255,000 related to other corporate expenses, including board fees, corporate office rent and insurance and $273,000 related to legal, accounting and other professional fees.
Pension related costs remained flat at $158,000 for the three months ended September 30, 2022 compared to the three months ended September 30, 2021. These costs represent professional fees and other periodic pension costs incurred in connection with the legacy Syms Pension Plan (see Note 8 – Pension Plan to our consolidated financial statements for further information).
Cost of sales – residential condominium units increased by approximately $15.3 million to $16.7 million for the three months ended September 30, 2022 from $1.4 million for the three months ended September 30, 2021. We closed on six residential condominium units during the three months ended September 30, 2022 as compared to one residential condominium unit during the three months ended September 30, 2021. Cost of sales consists of construction and capitalized operating costs that are allocated to the respective condominium units being sold, as well as closing costs of the residential condominium units.
Depreciation and amortization remained consistent at $1.0 million for the three months ended September 30, 2022 and 2021. For the three months ended September 30, 2022, depreciation and amortization expense consisted of depreciation for the Paramus, New Jersey property of approximately $287,000, depreciation for 237 11th of approximately $412,000 and the amortization of lease commissions, acquired in-place leases and warrants of approximately $309,000 for 237 11th. For the three months ended September 30, 2021, depreciation and amortization expense consisted of depreciation for the Paramus, New Jersey property of approximately $286,000, depreciation for 237 11th of approximately $381,000 and the amortization of lease commissions, acquired in-place leases and warrants of approximately $334,000 for 237 11th.
Equity in net loss from unconsolidated joint ventures increased by approximately $14,000 to $14,000 for the three months ended September 30, 2022 from a zero balance for the three months ended September 30, 2021. Equity in net loss from unconsolidated joint ventures represented our 50% share in The Berkley, which was sold in April 2022, and our 10% share in 250 North 10th. For the three months ended September 30, 2022, our share of the net income is primarily comprised of operating income before depreciation of $171,000 offset by depreciation and amortization of $115,000 and interest expense of $72,000 for 250 North 10th. For the three months ended September 30, 2021, our share of the loss is primarily comprised of operating income before depreciation of $451,000 offset by depreciation and amortization of $360,000, interest expense of $188,000 and the income from the change in the fair market value of the interest rate swap of $97,000.
Unrealized gain on warrants decreased by approximately $1.6 million to $64,000 for the three months ended September 30, 2022 from $1.7 million for the three months ended September 30, 2021. This represents the change in the fair market valuation of the warrants due mainly to the change in our stock price on the measurement date.
Interest expense, net increased by approximately $1.2 million to $3.6 million for the three months ended September 30, 2022 from $2.4 million for the three months ended September 30, 2021. For the three months ended September 30, 2022, there was approximately $4.9 million of gross interest expense incurred, $1.3 million of which was capitalized. For the three months ended September 30, 2021, there was approximately $5.5 million of gross interest expense incurred, $3.1 million of which was capitalized. The decrease in gross interest expense was mainly due to overall lower average borrowings during the three months ended September 30, 2022 compared to the three months ended September 30, 2021 from the on-going paydown of the 77 Mortgage Loan and repayment of the Berkley Partner Loan, partially offset by higher overall interest rates on our loans after September 30, 2021.
Interest expense - amortization of deferred finance costs increased approximately $494,000 to $763,000 for the three months ended September 30, 2022 from $269,000 for the three months ended September 30, 2021. The increase was principally due to less capitalized amortization of finance costs for our loans and secured line of credit as part of residential condominium units for sale.
We recorded an $82,000 tax expense for the three months ended September 30, 2022 compared to $47,000 of tax benefit for the three months ended September 30, 2021.
Net loss attributable to common stockholders increased by approximately $2.8 million to $6.4 million for the three months ended September 30, 2022 from $3.6 million for the three months ended September 30, 2021. This is a result of the changes discussed above, principally due to the lower unrealized gain on warrants and increased operating and interest