User blog comment:Kuzz/The Pulse - Week 4/2015/@comment-25956839-20150125235432/@comment-25660508-20150126094314

Only those who saw them in the past knows that PR data is archived in older versions, In the game you can only see one upgrade PR. Depending on that people want to upgrade. As someone pointed out in earlier comments no one wants to spend extra gold than required to complete a series.