Since you don't want to keep the vehicle, you could simply turn it in and be done.  However, there is a better strategy.  Remember, when you lease a vehicle, you have a preset residual, and you have the right to purchase the vehicle at the end of the lease for this residual amount, or in this case $15,000.  Since the vehicle is worth $17,000 less selling expenses of $500, you can buy the vehicle for the residual, turn right around and sell it, and reduce your leasing costs by $1,500.00  Table 2 shows that the total cost to lease under this scenario is $17,337.20

In the final analysis, the cost to purchase is $17,385.68 and the cost to lease is $17,337.20, which are basically the same.  Please note, that since the residual is set at the beginning of the lease, it doesn't matter what the value of the vehicle is when it is greater than the residual.  It could be $30,000 and you could still recapture the difference between the market value and the residual.  You do not have to had purchased the vehicle in the first place to capture this gain.  This is one of the advantages of leasing.