You are comparing areas in the Metro DC area with varyied real estate values, and from a job perspective varied socio-economic conditions. Charles County has reasonable housing, and fairly respectable socio-economics. Baltimore City gives you access to some affordable housing in Howard and Harford counties, but depending on the school, could leave you with some very troubled kids.
My advice would be to look at which school you would enjoy most, and you can always find housing though not reasonable by Buffalo standards, is commutable.