Perhaps the new lease price should be based on the current one adjusted for the age of the aircraft (i.e. +1 year older plane)?
1 million is a steal for a 777. 2.8 million is more along the lines of the "market" price for them, which is why few players can fly them without bankrupting.
As far as renewal costs, the new lease value is computed based upon the "calculated value" of the plane that you're leasing. That value tends to decline based upon age (but is increased by inflation) - so a brand new plane might have a "value" of 100m, whereas a 20 year old one with the same specs might be at 50m.
When you do the initial lease from the used market, the lease is calculated based upon the price put in by the seller, but you should also be able to see the "calculated" value, so you'll know at that time whether you want to lock into a long lease or just do a short term one (as this pricing adjustment is very handy if you lease a rarer plane for more than its worth, the lease rate drops at the renewal instead of increasing)....