To follow up on the concept of the time value of money, here is a simple thought experiment.
Imagine you owe a friend $1,000 per year for the next 20 years. By the time the twenty years is up, you will have paid out $20,000.
But what if your friend wants you to pay off your debt today -- should you give him a check for $20,000? Of course not. Because of inflation (and other issues), $1,000 today is worth more than $1,000 will be worth a year from now. And it is worth a lot more than $1,000 will be worth in 20 years.
So if you paid your friend today, you might give him $1,000 for this year's payment, but you would decrease the value of each subsequent payment that gets accelerated into the current year. The further out into the future you go, the less money you are willing to pay today. This is called discounting. If you ever bought a US savings bond for $86 that pays off $100 five years later, you saw this concept in action.
In the case of 2057 contracts, those extra 15 years are way out there -- some years are 45, 46, 47, 48 years in the future. You are paying for those points today, so you are not willing to pay as much for 2055 points (for example) as you would pay for 2012 points. It's not just a financial concept, it's also common sense.
That helps explain why the premium for 2057 contracts isn't as great as many people expect. You can see this reflected in the prices for OKW resales, since 2042 and 2057 contracts are selling concurrently.