NO way, the Airline is responsible. Thai Immigration has no problem with your expiration as long as you leave before the date admitted, but the Airline will refuse your boarding.
They make money on exchange rate too, so why asking USD10.-. Obvious THB500.- is better for them, but I guess it comes down to the person who run the show there and the agreement about their own revenue sharing.
Unfortunately you did not indicate the dates, but on 1st Jan you can do the first entry in 2018. The law specify TWO land border entries for 30 days per calendar year.
It looks that they start to get problems with their good "friends" from Mainland China. What I do not understand that Westerners or Russian need to overstay, it is plain stupid. If you take a little time and study a little bit the visa rules you will find many option to be suitable to you and your budget.