I don't think this is call white-hat SEO practice. White Hat is not directly purchase links but they do content + innovative way to get other people links to them. Link purchase is against the Google policy.
Do you think if Google educates to publishers and web masters to use Rel="Original" , the contents which are similar will be put it as considering set, use this tag as the best practice as similar to Rel Canonical tag that will help Google to identify the original content and make the search quality better?