Air King box fan = $30
Electric space heater/fireplace = $120 or less
8000 BTU AC = $180 (this is the worst time of year to be buying one of these things)
5000 BTU AC = $100
A dehumidifier is expensive, but that shouldn't be too badly needed. Summer heat, combined with intermittent air conditioning and fans, should dry things out during nice weather. During cold weather, the air outside is dry enough to keep everything bone dry.