yeah 500g will give you quite a few runs, at least enough to tell you if you want to continue using it or not.
If you want to save a few bucks, I’d get the B80 from @Killa12345. It’s way cheaper and you’ll get it much faster Pure-Flo® B80 BLEACHING AND DECOLORIZING BENTONITE CLAY – Quality Stainless Parts
this thread has a ton of R&D and will keep you busy for a few weeks Indofabs C.R.C & BHO Color Remediation Tek
your first run will turn that around completely! I was blown away by the results and now I use it every time on good material.