$390,000 buys the median home in Charlotte right now. With 20% down, that's a $78,000 down payment and a $312,000 loan, set against a $72,000 median household income.
Property taxes in Charlotte run 0.87% of assessed value, below the 1.1% national average. On the median home, that's $3,393 a year, or $283 added to the monthly payment.
North Carolina levies a state income tax on top of the $2,468/month this mortgage runs. Model your real after-tax take-home before deciding how much payment you can carry.
Charlotte's cost of living index is 101, above the 100 national baseline. That's on top of the housing numbers above, not instead of them.
Charlotte's median home price runs 7% lower than nearby Raleigh: $420,000 there versus $390,000 here.