When calculating Buy Costs we tally up money that will be out of pocket. We include what you'll need to bring to closing, all mortgage payments and maintenence charges.
When you own your home you pay towards your principal, your house appreciates and you get yearly tax savings. We take those amounts and subtract them from your
"Buy Costs" because they offset what you're spending when owning your home.
Here's a look at your buy costs for this scenario.