I bought a $560K home with a $400K mortgage. (equity from previous home.) HHI is $100K in salary/bonus plus about $15K in child support. Finances were more comfortable when I had a renter in a spare bedroom, but we do ok without it.
Personally, I'd look at what you're paying now in rent or mortgage, add whatever you could pay and still be comfortable, and then see what that buys you in terms of mortgage/tax/interest. Also, don't forget maintenance costs, especially if buying an older home. I'm a Home Depot a LOT for my 70-year-old home.