Just looked, and for the weekend of 11/12 it's $41 to walk 18 during the prime morning weekend spots. (with player card and winter rates) Typically like $54-70 in the summers depending upon day/time IIRC

Already been said, but check out Pine Ridge, up by Loch Raven, that was our regular course before we joined an affordable club up there. The Baltimore County courses are a bit more expensive but maybe a little nicer

Forest Park, Mt. Pleasant, and Clifton are solid, affordable courses. Carroll Park is a great place for a 75 min 9 holes in the morning before work, or if you are learning. Short but fun and very cheap.

Totally worth getting the player card, for either the Classic 5 courses (4 courses in the city + Pine Ridge) or the Baltimore County courses. Pays it back very quickly in my experience