Agree with OP right above this post.
Tesla does not want cars back, thus high interest rate and low residual. They want you to own the car, e.g. below market 1.5 for 6 yr loan rate.
Although complex it is simple too-buying 109k car, lease pay 50k over 3 yrs plus tax and interest = 55k/36mos=1525/mo (rough numbers to make point).
Purchase 110k/72mos=Same payment.
Then you get the tax credit and state incentives (assume you can use them) makes the buy monthly equal less. Downside is you are committed double time to payments but likely to get those second half payments back at sale (can’t imagine a 6 yr old S going for less than 40 but we’ll see).
I purchased my S in 12/17 and love it but this is a hard step to get through. BTW if you make biweekly payments instead of monthly you will own it 6 mos earlier and save more interest.
Congratulations in advance.