I agree about the egress. You must have two ways out of the basement. If you don't have a exit consider digging one out. Don't put bedrooms in the basement unless their is an unobstructed exit.
Best of luck to you.
Benner Geo Tech out of Frederick does great work (301-696-0547). I've had radon remediation systems installed for $250 up to $900. The cost is a function of how hard it is to install the pipe from the basement to roof and other factors.