The lease side uses the capitalized cost, residual, money factor or rate, and term on the form. The buy side is an amortizing loan at the loan rate you enter on the same vehicle. The page compares the payments and the cost over the term you set. Taxes and fees count only when a field includes them.
A higher residual lowers the lease payment and leaves you without the car at the end unless you buy it for that residual. The loan payment buys the car and continues until the term ends. The comparison is those two sets of inputs, not a dealer’s worksheet.
Disposition fees, excess miles, and wear charges are not estimated. Sales tax is included only in the fields that ask for it.