Metal Dwellers is the trading name for a hardware partnership. Metal Dwellers runs a fleet of three delivery vehicles which need replacing. Metal Dwellers can borrow funds to buy vehicles costing $120,000 in total for 7% pa after tax, compounded semi-annually. Alternatively, their financier will arrange lease finance over 3 years with 6 semi-annual payments of $15,000; the first payment to be made when the lease is signed. A residual payment of $45,000 will secure ownership of the three vehicles if Metal Dwellers decides to buy them at the end of the lease period. This value is considered to be fair market value for the vehicles. Metal Dwellers' owners pay tax on average at the rate of 25% and pay an installment of tax every quarter. Assume for simplicity's sake that the tax benefits from each lease payment and the tax benefits forgone for depreciation are received without time lag in each half-year period. Should the vehicles be leased or purchased