My guess is that the average Thai makes less than the average US or European. So they price them affordably so people can buy them. Heck why not. They've already made back the investment in the US. Everything else is gravy. Besides, the disks only cost a buck a piece to burn in quantity.
Seems sensible. I haven't priced DVD's here yet. I have noticed machines that look like ATMs but seem to be about renting DVDs. I gotta figure those out.