Every upgrade adds to the price, and so to your payment for the life of the loan.
Homes that are already built have their upgrades picked. Builders sometimes include more upgrades in those homes to sell them.
Pay for the things that are hard to add later, like the layout, extra outlets, plumbing and ceiling height. Things like paint, lights and faucets are easy to change after you move in.
Every upgrade adds to the price, and so to your payment for the life of the loan.
Homes that are already built have their upgrades picked. Builders sometimes include more upgrades in those homes to sell them.