Should I apply for a working visa or come on a holiday visa to sell my books at a book fair in Thailand?

This is kind of a hypothetical at the moment.. But would like some help in regards to what I should do..

Later this year I am applying to exhibit and sell a few of my photographic books and a handful of prints at a book fair in September. The fair runs fro 3 days only.

So my question would be do I apply for a working visa? Or do I just post the books to the hotel and come to Thailand on a holiday visa as I’m only selling for 3 days and might be lucky to make $200AU for the 3 days?

Thanks for the help