I'm on the $20 plan too and the only time I run over is if I'm using Opus (or probably other third-party models). Grok and Composer seem nearly free at this point. Cursor also gave me a $100 credit for Grok after 81% of my usage was on TP models. I don't think Grok 4.6 is quite at the level of Opus 5, but it's close and so much faster (and less chatty).