A lease is directly proportional to the price of the carIt has nothing to do with the price of the car man it has to do with how much the total amount is that you are financing. If you put down 5k on an 85k car you are financing 80k hence the 1400/month. In this case, putting 25k on a 150k car you are financing 125k thus the higher payment. The only difference between financing used vs new is that typically the money is cheaper on new cars.
Also, leasing a used car is a horrible idea. The rates, money factor and residuals are horrific.
Spreading the tax across the payment is also a bad idea.. If the car is totalled or stolen, you have to fight with DMV for your money back.