its not cheaper because then you will essentially have paid the depreciation off + tax on the payments, + tax again on the purchase of the remaining balance, thus turning your $26k car into a $30k car, no? Im obviously using rough numbers here as I don't know what the capitalized cost was on your GTI, your money factor, anything..
also, the interest rate comparison doesn't add up anyway from C4L because if OP has good credit, he can get a money factor comparable to what we got which ends up being about .036% APR vs. best case financing on a used car which will be, at best 1.9%, if you are willing to finance for the shortest term possible thus making your monthly payments huge. or you can put money down on the remaining balance on the GTI/buyout, but then thats money you are sinking into a 3 year old GTI, which may or may not be fine, when you could just pocket the money and get into another lease. cash in hand will always be worth more than cash in a car, unless you are trying to lessen the long term hit of finance charges, which in OP's case, is irrelevant
i do agree that with the mileage factor and end condition of the car, you can definitely walk away with some equity whether its just cash in hand going into your new lease or buying out the car. if you get a vw or audi that $350 return fee is waived btw.
I just dont think buying the existing car is 'keeping any profit for himself'. I totally agree with the bolded part, but a better option IMO would be to sell the car himself at lease end and keep the difference in equity i.e. cash in hand. OP just sounds like a good lease candidate to me. So if his GTI ends up being worth $2500 more than residual, he'd be better off having the $2500 and getting into another VW w/0 down for another 3 years vs. putting that $2500 into buying out his GTI.