This is an interesting but probably impossible question to answer. I say this based on my own evolution from a bright-eyed MSTP student in my early 20s to a burned-out senior resident in my mid-30s with a spouse, kids, and extended family spread all over the country.
My wife and I have 2 main geographic regions where our families are based, and an additional 1-2 we would consider based on affinity/experience etc.
This is actually a question I ask myself constantly. Say I beat the odds and am offered a position in my #1 choice region. Say I am somehow even luckier to get offered a second job in a region I'm not really interested in but the pay is significantly more. How much money would it take for me to turn down my preferred geography for money?
The rate limiting step is really my wife and spawn. If I was single, would I go work in ultra-rural Wyoming for $500k? You bet your sweet butt I would, I love wide open spaces and hate cities. However, Wyoming is A LONG LONG way away from my family. Will my wife tolerate this even for $750k? More? She might initially agree but then come to hate the fact that trees are her only friends. What about my miniature genetic vessels? What are the school options like?
You'll come to find that it will NEVER be as simple as "money vs geography". Especially in RadOnc in 2020 and beyond. At this point, my only option might be a rural Wyoming position for $200k, and I'll be happy to take it because children require food.