The note or lack thereof has nothing to do with it. The time value of money is the same regardless of where the money comes from. We are figuring the future value of a payment today. The formula tells you the value of some number of dollars at some future date (the number of years is the power in the formula) It doesn't matter if you pay cash outright, the $$ today are still worth practically twice as much 10 years down the road if you assume a real interest rate of 7%. If you look at recent history I think 7% is not too far off...interest at around 8% with 1% inflation. Perhaps that's just a little high, but not much.

You can turn the equation around and say that you think the resale value is going to be $30,000 greater when you sell it ten years from now, and work backwards to find how much more that is worth today, also. My calculation says that you can pay an extra $15250.48 today and break even in that example.