once the script is finish i send half then when i see it working ill send the rest only serious people thank you i will give you the script idea once we get settle on the job on hand
That's not how it works, someone can only quote you/give a price estimate for the script once they've heard the idea.
The first part I need to clarify. Once you receive the script, you pay half and
once you've verified that it does what you asked, you pay the rest. Payment for a script you commissioned should never be dependent on you making profit from that script.