My first question is what are you paying in rent or house payment right now? Are you comfortable with this payment and if so, then call your lender to find out how much house you can purchase with that house payment. I know it sounds a little backwards. But most buyers get so caught up in what is the biggest house or most expensive house I can get based on what I make. Instead of thinking about it the way we really spend money. I had a recent buyer who qualified for $425,000, but after I sat down with her and she really started looking at her lifestyle, well...we were looking at houses in the $325,000-$350,000 range. You don't want to be house poor!
This might not been exactly what you were asking, but I hope it is insightfull advice.