Posting links to X through custom social media software just got a lot more expensive. On Monday, X significantly increased how much it costs to post a URL via the X API, which is what third-party tools use to hook into the platform. It now costs $0.20 when a link is posted, up from $0.01. Any change to make posting links more expensive will likely make X even less attractive to publishers than it already is, especially given the widely held suspicion that linking news articles can lower a post’s reach. The issue came up in a recent spat between Nate Silver and X’s head of product, Nikita Bier, who claimed that links are “not deboosted.” But a recent study from Nieman Lab analyzing posts from 18 large media outlets found that links “do seem to hurt news publishers” on X. The price hike is already affecting a notable X account in the tech world: the news aggregator Techmeme. Until Sunday, Techmeme’s posts on X would have short headlines summarizing news and linking to the source.…