I'm not sure where the 30% comes from either. I've seen it often thrown around for housing markets but it seems out of touch, since it doesn't line up with a l

I'm not sure where the 30% comes from either. I've seen it often thrown around for housing markets but it seems out of touch, since it doesn't line up with a lot of median incomes of home owners vs median prices in metro areas. It's not uncommon to see many people putting 50% of their income or more to rent, so why would mortgage be different?