What is the ruling on buying foreign or Arabic movies? Is it permissible to buy them if the presence of something unlawful is not clear, or if the percentage of unlawful content in them is small, and what are the limits of this percentage?

What necessitates prohibiting the purchase of the aforementioned films is that they contain impermissible elements that render their viewing unlawful, such as the exposure of 'awrah (private parts) and the promotion of evil. It is rare for films and TV series to be free of these. Ignorance of their content is unlikely, as their content is known from their advertisements or by asking about them. If a film contains impermissible elements that prohibit its viewing, then purchasing it is absolutely impermissible, unless it is something minor and unintended that can be overlooked.