Instruction as a first job is an excellent way of building hours and experience, it makes you a much better pilot than you will be with 200hours. BUT!!!!!! as a route into the airlines it is now bollocks, the hours for many airlines are a hindrance now, take BMI regional, not employing pilots with over 500 hours at the moment.
Whether you instruct or try and get a job with 200 hours it makes no difference at the moment.