Dear Sir,
I want to do this, if you give me this job?
Then I'll do the job very carefully. I do not have any money.
If you like my work, then give me whatever you want.
I have a 10-year experience about this project / job.
If you are not satisfied with any work, you will change me as often as you ask me to change.
I want to be a professional freelancer .... if you give me a chance.