Paying off future plane orders without the "penalty"

[swiftus27]

I paid 80% up front and I owe just under $1.6m on a 707 that is coming in.   I choose to change my order to 100% down payment.   Boeing wants $2.2m

This has got to be one of the dumber issues we can easily fix, I am sure. 

How to fix it?  change the algorithm so that one would pay off only the remaining balance owed but receive no benefit for doing so like they would have if they'd paid it up front.  Charge a $49 processing fee.