I will definately buy nail polish thinner on my next trip abroad,since I don't see that selling in my country,tough I was always negative about putting nail polish remover in my nail polishes 'cause I feel it's ruining my nails.
As far as thickness of nail polishes goes,I'm starting to think that maybe it has to do with the place they are produced.In my country for example,I never buy perfumes because they are not as good quality as when I buy them somewhere abroad,and maybe same thing goes for nail polishes.