Home prices in South Portland run in line with the national median: $420,000 versus $420,000. Relative to the $70,000 median household income here, the price-to-income ratio comes out to 6.0x.
Property taxes in South Portland run 1.08% of assessed value, below the 1.1% national average. On the median home, that's $4,536 a year, or $378 added to the monthly payment.
Maine levies a state income tax on top of the $2,742/month this mortgage runs. Model your real after-tax take-home before deciding how much payment you can carry.
South Portland's cost of living index is 112, above the 100 national baseline. That's on top of the housing numbers above, not instead of them.
South Portland's median home price runs 13% lower than nearby Portland: $485,000 there versus $420,000 here.