If a foreigner goes to the US and rents a car or motorcycle without an IDP and valid license (car if driving a car and motorcycle if driving motorcycle), then the fine is going to be more than the equivalent of 1000 THB.
Just saying, that when foreigners come here without either driving experience on a motorcycle or a motorcycle endorsement on their home country license? They put themselves and everyone around them in danger. So, imho, the 1000 THB fine fits.
Fyi, when I first came here 15 years back, I came with my US drivers license with M/C endorsement and a IDP. I was stopped at road blocks during that time, show my licenses and IDP and was on my way.