Income = $2000 / month, no debt
$2000 * .36 = $720 theoretical maximum monthly payment
$720 * 12 months * 30 years = $259,200 theoretical maximum home value (and of course not taking into account interest and various other fees and costs)
This means that I could qualify to borrow this adorable cottage in Oregon for $244,900... as a single income-earner getting $12 an hour. I'm actually not that surprised because I know mortgage companies encourage home-buyers to take out as much debt as possible, but it still feels ridiculous to be able to get that much house, even theoretically. (Excuse me: borrow that much house.)
What factors could influence the cost of the house? - Normal things, I guess. Location, mostly. Size, quality, upgrades, local schools, and crime rate.