How Low Interest Rates Increase Your Purchasing Power. Often, the easiest way to understand this and see the impact that rates have is visually in a chart or graphic form. Take a look at today's article and the rate chart that clearly demonstrates higher vs lower rates do for you. If rates move up, given the same payment, you get less house or have to put down more money to keep the principal down and the payment affordable. Bottom line, now is a really great time to lock in the mortgage and get the home that you want - while you can still get more of it!