Possible 2012 650i x drive lease swap

Hey guys -

This is just an idea, but I'm thinking about switching over to a four door. I've only had my coupe for a few months, but it looks like my wife and I are going to try and start a family sooner than I orignally thought. With the current holiday incentives it looks welcoming, but I would have to find someone to transfer my current lease to. I've laid out all costs I paid and what it would cost for someone to get into a '13 with the same options, given what I put down on my '12. I'm sorry for the detailed info, let me know if anyone might be interested. Thank you!

2012 650i X drive-

Carbon Black Metallic
Black Nappa Leather
Gray Poplar Wood
Cold Weather Package
Full LEDs with 20"s
M Sport
B & O sound
Heads up Display
Instrument panel w/leather
BMW apps
ARS
Shadowline
Ceramic Control

MSRP - $106, 495
12,000 Miles a year - 36 Months
Lease started 7/1/2012
Currently 3,300 miles
Residual is $68,156
Total monthly payment = $889.14 (I paid tax upfront)

This is what I would be looking for to get out....

Lease fee $250 (I will pay $250 and split)
I paid $4868 in cap reduction ($135/m x 6 months(what I've used) = $810
Cap Reduction reimbursement $4000
I paid $3600 for 4 MSDs - this is returned at the end of the lease
I paid $2926 in taxes up front ($81/m x 6 months) = $486
Tax reimbursement $2250
I paid $725 for ED fee, $369 Doc fee, $350 for NYS reg fee. I will eat those.

Total out of pocket = $250+$4000+3600+2250= $10,100 ($3600 of which you'll get back)

Now to compare a '13 with the same options and putting down the same money....

2013 650i X drive
Cold weather
Executive package
Full LEDs
M Sport w/20s
B&O
ARS
MSRP= $108,095
57% residual for 36mos, 12k year
$3500 options credit
$700 loyalty credit
(Cap reduction $250+$4000 from above) $4250 + $600 (reduce MSD from above, 3600 to 3000. Use the 600 to get monthly pymt below 1000)
Tax payment from above $2250
MSDs from above $3600-600= $3000

Sale price $750 over US invoice = $99,895
Cap Reduction- $4850
Options credit + loyalty= $4,200
Net Cap = $90,845
Residual 57% = $108,095 x .57 = $61,614.15
Depreciation = Net Cap - Residual $29,230.85
Dep Cost = $29,830.85/36 = $811.97/mo
Net Cap + Residual = $152,459.15
Money Factor = .00135
3 MSDs = .00007 x 3 = .00021
Final MF = .00114
Finance pymt = $173.80
Total Monthly pymt before tax = $985.77

Tax on Final Pymt = $985.77 x 8% x 36mos = $2,839.02
Tax on Cap red/options credit = ($4850+4200) x 8% = 724.00
Total Tax = $3,563.02
Apply my tax payment above $2250
Remaining tax = $1,313.02

Cash Breakdown -
Cap Reduction - $4850
3 MSDs - $3000 (refundable)
Tax - $3563.02
1st payment - $985.77
Dealer Fees - $369
State reg - $350
Total Out of pocket = $13,117.79 ($3000 refundable)
Total Monthly Pymt = $985.77

Unless I'm missing something, the swap would be about $3k less upfront assuming you paid similar costs upfront and save about $100 a month. Thank you for looking.