You may want to tidy this up a bit and use it to create a lease proposal. If you like it, send it to another dealer. This is the complete package. Some of this is for your eyes only…
Input Data
MSRP 66320.00
Sales Tax Rate 8.00%
RV (59%) 39128.80
MF .00219
Term 36
Total Rebates 8500.00
Trade Equity 8500.00
Calculations
Sell Price 61014.00 (8% dealer discount off MSRP)
Capitalized Fees 0.00
Gross Cap 61014.00
CCR- Rebate 7130.00
CCR- Trade Equity 8500.00
Adj. Cap 45384.00
Base Payment = .00219 x (45384.00 + 39128.80) + (45384.00 - 39128.80)/36
= 358.84
One-Pay = 36 x 358.84
= 12918.24
Lease Inception Fees/Credits
*One-Pay 12918.24
*Doc Fee 250.00
*Acq Fee 795.00
*Convenience Fee 50.00
Total Sales Tax 1691.46 (includes tax on 7130 partial rebate cap reduction)
Reg/Title/Plate Fees 125.00
Alternative Fuel Fee 150.00
Trade 8500.00
TOTAL 24479.70
Rebate Credit 1370.00
DAS 23109.70
Customer Cash Due 14605.70 (included in DAS)
*Taxable Fees
Purchase Option Calculation if Exercised within 30 days of Lease Inception…
Input Data
Constant Yield Rate 6.2386%
RV 39128.80
Term (N) 36

NOTE: The above ALB calculation captures unearned rental charges. Deducting unearned rental charges from the RV requires an amortization schedule and will result in an ALB equal to the ALB computed above. For this reason, the above calculation is much simpler and more straight-forward.
An alternative ALB calculation is as follows…
Initial balance = Adj. Cap – Single Pay
= 45384.00 – 12918.24
= 32465.76
Because lease payments and rental charges are fully earned one month in advance, the adjusted lease balance within the first 30 days of lease inception is just the future value of the initial lease balance 1 month into the future…

Buyout = (32634.53 + PO Fee) x 1.08 + admin fees/taxes (See lease agreement)
Interesting side note…
Observe that if the lease goes full term, the adjusted lease balance equates to the residual value (RV)….

Miscellaneous
You can also use the PV function in Excel to find the Adjusted lease balance (ALB) for the single pay option…
ALB = PV(RATE, # of months remaining, 0,-RV,1)
Using the Excel RATE function with the following syntax:
RATE = RATE(term, -(ACC - Base Single Payment Option), RV, 1)
Annual Constant Yield Rate = 12 x RATE
ACC = Adjusted Capitalized Cost
You can even use the TI-84 calculator
TI-84 Calc…
N = 36
I = 6.2386…
PV = -(45384.00 – 12918.24)
PMT = 0
FV = 39128.80
P/Y = 12
C/Y = 12
PMT: BEGIN