If I'm reading right, the $7K school is not close enough to home to live with your parents, so at that school, you'd have living expenses on top of tuition during school, and living expenses during residency. Back of the envelope calculation for that scenario: $2K/month living expenses times four years of med school = $96K in loans to cover your living expenses during med school, plus $28K in loans to cover your tuition = $126K in loans for med school. Then you'd have another $96K in living expenses during a four-year residency, which along with taxes would eat up most of your take home pay (let's assume $50K/yr gross, $36K/yr after taxes minus your $24K/yr living expenses), leaving maybe $1K/month discretionary, of which about $600 would go toward interest on your loans, and $400 extra towards principal. You could pay down about $19,200 ($400/mo times four years) of your $126K loan principal --> $106,800 balance.
If you went to the $50K school and found a residency in the same city and lived with your parents for the whole eight years and they paid for housing, clothing, food, misc., you'd have $200K in loans for tuition. The interest on that after med school would be around $1K/month. You'd have $3K/month take home pay during residency, out of which you'd pay about $1K/month in interest and could put another $2K/month toward principal. In that scenario, you could pay down about $48K of your $200K loan principal --> $152K balance.
I'm obviously just ballparking the numbers, and the financial aid offices at each of these schools should be able to help you fine tune them for a more precise comparison, but the $7K school looks like a better deal, plus you get to live on your own, plus who knows, maybe you move in with someone along the way and your living expenses go down and the delta becomes even greater. Plus your very generous parents might pitch in along the way and help you come out with less debt --> lower monthly interest --> faster paydown of principal even with the same overall monthly payment.