A fee to get the license but very cheap (100 bahts). Without license you will not be allowed to export it, in case they find it in your baggage.
Better to do as I did, maybe they'll give you the license, and if they don't give you the license you'll do your own way then !
Probably many people export without license, but if you're caught you'll have to leave it in Bangkok, which doesn't really matter if the statue has no value.
I may not insert the link from the Bangkok Post. Google for it with "Exporting Buddha"
https://www.dfdl.com/insights/news/what-are-the-rules-regarding-exporting-buddha-images-from-thailand-dfdl-article-in-the-bangkok-post/