Or you could just put how much it would cost big and clear on the job posting. Not hiding it behind a secondary link that needs to be clicked.
then there is the whole "yes I am interested, tell me more" and back and forth, then they bail with no thought, but it costs us for their being unsure!
I am not sure what trade line you are in, but have you noticed that the leads are more vague now causing us to contact more people just to try and get work. Then is the customer writes back to explain what they need we are charged, but maybe the job is out of our scope. Paid for something we cannot do.