800k loan on 100k salary is not only unreasonable it’s not possible to be approved in today’s market. A 500k purchase with 200k down is a 300k loan and close to half of your take home pay, so that’s your ceiling. If she can’t understand that and wait for either the prices to come down or your income to go up, you have two options. Tell her to get a 100k job and find another 200k cash or re-evaluate the statement “short of a divorce.”