A “Rule of thumb” is just that and you need to look deeper. Here’s an extreme example_ say you make 50K a year but just inherited $10M. Should you just limit yourself to some multple of your income. I know this is a silly example but the truth is you really need to look at the total payment relative to your income to make the best decision.
I also dont know whether you will be able to buy low in high interest rate environment and refinance later to rates anything approaching where we are at today. Whose to say prices arent low today either? In some parts of SD, they seem to be. It all depends where you are looking. The best advice is to buy something you love that will keep you happy for the next 5 to 10 years if not longer. Something that you can easily afford and something that is close to buy vs. rent parity.