Optimally, you should spend only about 25% of your after-tax income on your mortgage payment. Although there are loans you can get for nearly half your income going towards your mortgage payment, the less you owe on your mortgage, the easier it will be for you.
There can be be extra expenditures you hadn't planned on, so it is best to have extra money in your budget. In addition, financial planners recommend you always have in savings 3-6 months of expenses should you need it.
Additionally, the larger down payment you have, the less of a mortgage you require, and the lower your payment will be.
You will Pay Three Times your Mortgage Over Time
By the time you have paid off your thirty-year mortgage -- you have actually paid it three times over. The interest you pay triples the total amount you pay. That's why it is best to have as large of a down payment as possible, to minimize your payments.
That is also why it is good to pay down your mortgage early. This will decrease the amount of interest you pay over time.
Down payments used to be 20%, but many lenders today allow buyers to own a home with very little down. The disadvantage to that is that buyers may not feel as invested in their purchase as they used to be.