Let's see if I can make this read correctly.

My residual is a bit over $20k and my payment is $305 + sales tax. The interest rate is so close to zero percent that I won't even look it up. At the end of the lease I can pay a $300 fee and walk away or I can buy/finance the car for the $20k residual.

However, if the actual value of the car is much less (say $15k) I should walk away... and then come back in a few days and buy the same car for $15k and save the $5k difference. The dealer knows this too. I have not run a lease before, but several folks have told me that the dealer WILL re-negotiate the terms at lease end in this situation. 8)

Since I couldn't convince myself that I would really want to keep this car after 3 years, I see this as a perfect way to leave me a simple out. If I leave I will have paid $14.5k for 39 months of fun driving and no interest costs. The total of sales taxes at this point will have been only $1200.