Why do I feel like you're talking about Brown's Criminal Laws: Materials and Commentary? Edit: My bad, you're talking about business.
Generally speaking, for engineering, IT, mathematics and similar subjects in which content doesn't change much, one or max two editions doesn't make a difference (I know an engineering student who got away with a 2002 textbook where a 2014 edition was recommended).
However, for business and law and subjects like that you actually need the newest edition since you should be aware of the most recent changes.