Depending on what 5x is, you might not annoy as many users as you think.

I did a major pricing overhaul with my SaaS company a few years ago and made lots of sincere appeals to users. They generally supported me and the app. I had some churn, but I knee it was coming. It worked out for the best.

Of course, my experience is going to be unique but with the right transparency and explanation you may be overcome a lot of reflexive pushback.