When I look at the interest rates on various savings accounts, they are all way lower than the 4.6 percent I'm being charged on my mortgage. I do recognize my condo as providing me with a service, and my minimum payment now is actually less than the rent I was paying on a studio 4 years ago! But, if I think of the equity I gain as a sort of savings account for a future upgrade, I'm just not sure how to compare my options. The simplified thought process I currently go through is that any extra I pay on my mortgage saves me 4.6 percent in interest that I would have to pay, while that same money would only earn me maybe 2 percent in a savings account, so it is better to save 4.6 percent by never having to pay it. Am I totally off? Erin, Boston, MA