Abiraterone acetate (Zytiga) is an older. out of patent medication. so it's a relatively inexpensive generic these days

The newer ARSIs, the -lutamides, are far more effective for many (not necessarily all) patients, and don't require you to take a steroid with them, with all the extra potential side effects, but they're very expensive — especially in the U.S.

It's worth confirming with your oncology team that Abiraterone acetate (from any maker) is the best treatment for your cancer situation, and not just the best your insurer will allow. It might be so, but a frank discussion won't hurt. Steroids really did a number on me when I was on them to reduce spinal swelling, and I'm glad I don't have to take them with my Apalutamide.