I really like that Pale Rider image, John! Rarity of original release Thai posters is an interesting question having lived in Thailand a bit. I think you are wise to keep your radar up on what you feel is original release, especially on Thai posters for English language movies and you are spending what you feel is a lot. I certainly don't think I'm an expert on all Thai original release poster rarity, though when there's a want, need, or desire, even for the "rare", resourcefulness seems to abound there! Okie
Hey! Okie, glad your liking the Pale Rider image, it's certainly already a personal favourite Thai poster of mine.
I certainly do my very best to "keep my radar up" when buying "any" posters, but, especially Thai posters, I will always try and do as much research and checking around whether it's talking to fellow collector's on these very forums or elsewhere.
It's safe to say these latest two purchases cost a decent price to say the least, but, all I can say is I'm as confident as I possibly can be about every Thai poster I've bought to date.
If I'm ever a little unsure then I will always pass on a poster, for example I was recently offered a JAWS Thai poster but was not convinced it was genuine so I did not buy it.
I should also add that as well as doing my homework on each poster I buy I also try and do as much background checks as possible on any seller I decide to buy from, so hopefully doing these two things together means I can always do everything in my power to avoid picking up any fakes/reprints etc.