Thank you. That's so much better. I really don't know where he got that I would owe him 350k after paying for 64% of the house.The first thing that the two of you have to understand is that, if you don't reach an agreement, you'll have to sell the house.
My math is based on selling the house for $830,000.
You'll pay 6% commission ($51,000) leaving $781,000.
You get your $200,000 back from the loan payoff. He gets his $60,000 back from the loan payoff.
That leaves $501,000.
He gets $60,000 back for his down payment. You get $12,000 back from your down payment.
That leaves $429,000.
You get $38,000 that you paid into the principle. He gets $20,000 that he paid into the principle.
That leaves $371,000.
Divide that in half and you owe him $185,500
At 3% interest with a 30 year amortization your P and I would be $782 per month.
In your mortgage contract you could agree to sell or refinance after the kids are grown. At 5 years your balance would be $165,000. At 10 years $141,000. Shouldn't be too hard for you to refinance that amount.
If he won't go along with the adjustment for the commission and you don't want to risk having to sell the house, add the $51,000 to the $371,000 and you get $422,000. Divide that in half and you owe him $221,000. $932 per month. Balance at 5 years $196,400. At 10 years $168,000.
If you want to calculate 2%, use this amortization calculator.
Mortgage/Loan Calculator with Amortization Schedule (bretwhissel.net)
One silver lining to NOT being married appears to be that the courts can't easily force a sale if we can't agree, like they could during a divorce. Apparently, he'd have to lawyer up and sue me to force this to happen, and it can get *quite* expensive.
Is there any way to prevent that calculator in the link you shared from automatically including a balloon payment?