First, Posit (the company behind RStudio) uses a different version numbering system. There is no version 9.0.
If your goal is to learn R, write code, build statistical models, or analyze data, you do not need a budget. The official, full-featured desktop version of RStudio is free. Follow these steps to install it safely: Step 1: Install R (The Programming Language)
If you are a business or an academic institution requiring advanced infrastructure, Posit does offer paid tiers, but these are handled via official subscriptions—never via random string keys found online.