Are home prices cheap in your city right now?
It's common to answer this question by talking about how prices today compare with prices last year, or to look at how prices in your city compare with prices in other cities.
But there's another way to frame the question: Compare home prices with income. You would expect that the ratio would be similar in different places. In cities where incomes are higher, home prices should also be higher. In cities where incomes are lower, home prices should also be lower.