My friend (american) came here on a tourist visa (30 days) and it expired 8 days ago.

Can he go to immigration and get TWO 7-day extensions (one to cover for his overstay and another to cover it up until his departure)??

He leaves in a few days. Would you advise him to sort it out now or at the airport when he is about to leave?

He would have to pay 500 baht a day for overstay for a total of 4000 baht before they would give him 7 days to leave the country after applying for extension (1900 baht).

He would need to show a ticket out of the country in order to get the 7 days.

He should of made a border run to get a 15 day entry before he overstayed.

Do pigs fly? And he doesn't have a TR (tourist visa) bacause those are valid for 60 days (US) but more likely a 'visa on arrival'.

Even if his visa wasn't expired, he couldn't have got 2 extensions. But, at the discretion of the officer, they may accept applying for an extension retrospective which means he doesn't have to pay the overstay for the first 7 days.

Apart from the risk of being caught before entering the airport to skip a trip to Immigration, he might as well choose to pay for 15 days overstay at the airport which makes it a little more expensive but more convenient. But if the above works (not likely as the visa has expired longer than the 7 days extension), he only has to pay 9 days of overstay.

I personally have experienced multiple times to get an extension retrospectively even if the visa was expired.

He is on a 30 day visa exempt entry. A visa on arrival is for only valid for 15 days and only for those from certain countries plus a 1000 baht fee is charged.

Immigration will not back date an extension to eliminate an overstay ever.

There have been several reports of people going to immigration with a much longer overstay and then being granted the 7 days to leave the country after applying for an extension and paying the 1900 baht fee.