Are you sure you have a proper Tourist Visa? A sticker on your passport?

Get 30day extension at any Immigration Office

20 baht maybe because they make a couple of copy.

In Samui is 1,900.

Yes, Thomas.

METV works like that:

60 days on arrival

Border run to get 60 more days

Second border run to get 60 more days (total 180 till now).

After 59 days, get a third border run, getting 60 more days (total 240 or better 239).

On expiring day, get a 30 days extension at any Immigration Office. Total 269 days, nine months.

But you need to do 3 border run and get one extension (1,900 baht)

And some Consulate, for example Penang, also ask hotel booking (minimum 14 days) or house rental contract

Hmmm.. I think Jim will not be happy that someone publically say that...

Penang Consulate will ask you a hotel booking (at least 14 days) or house rental contract AND a return ticket. Visa fee is 150 ringgit, about 1,200 baht.

Tourist Visa is a sticker that takes a whole page of passport.

Why no more 1,900 ?

Yes, get 7days extra extension at Immigration, it costs 1,900 baht.

Better not to have overstay stamp on your passport (4 days overstay would cost 2,000 baht) and if for any reason you should be stopped by Police during those 4 days, could have big problems.