You cannot get the first 12 month extension of stay using the 65k a month method at many if any Immigration Offices. It has to the the Embassy affidavit or the 800k.
To help the OP and others use the correct terminology as Visa on Arrival (VOA) is 15 days and cannot be extended and Visa Exempt is currently 60 days and can get a 30 day extension.
That's a common question to be asked. I've been asked that many times over the years when entering under Visa Exempt, Tourist Visa or a Non-O Visa (marriage).