$1.52 The cost of a 44 mag bullit. Shoot the poor thing.
Seriously, Problems are idle when stopped in gear, transmission doesn't shift, service light is on (when its flashing that means you can be damaging something seriously).
Cost depends on make model and where is gets serviced. Transmmission module possibly, or torqe converter. How many miles on car and have you ever changed transmission fluid of towed anything?