Penalty for over staying visa question (Istanbul)

Hello all.

I am a Turkish citizen but my 15 year old son is a U.S. citizen. He entered the country on June of Protected content by Sept. I made an appointment for a residence here. The appt. was for Nov. Protected content when we went, they wanted his birth certificate which we didn't have.

We received his birth certificate in February of Protected content I made another appt. which was yesterday. When I went to apply, they told me rules and regulations changed and that he will now need insurance, my police record, the old appointment from Nov of Protected content . etc etc....

Schools did not workout for him here so he is planning on returning to the U.S. this July to finish his high school. I am now debating whether I should go through this trouble to make him a resident only to see him leave the country or if I should just pay the overstay visa penalty but I do not know how much penalty I would have to pay and neither does the foreigners office.

Anyone have experience with this situation?

Thanks in advance.