This is a fact. Content localisation requires more knowledge on your industry, market, product… and so it takes longer to get the right content for your target.
That is why content localisation may be more expensive than a simple translation.
But the right question should be : is the return on investment the same ?
Why do you communicate ? You have something to say and you want your audience to understand your message. So what is the point if your message is not understood ? In the end, content localisation with the right speech provides you with the best ROI for your spent in communication.