Ive used the cheaper gfo and the & Hc-gfo brs sells.I'd agree if you consider regenerating it the Hc is the way to go.The cheaper stuff brs sells will disolve in just a vinegar bath and imo, is a throw away product.
The quick math,-brs gfo is about 20$ whitch yeilds 4 cups.
,brs Hc gfo about 60$ / 4 cups.
So its about 5$ a cup for the cheap stuff vs 15$ for the hc.
If you regenerate it,I found the roeibec product was enough to regenerate 8 cups of Hc gfo @ 14$ a batch.
If I did the math right,the initial 14$ for roebec product ,using 1 cup per month of hc gfo will last me 1.5 years before having to invest in more roebic ,and the amount of gfo I have should last several years.
I know you didnt ask this but I thought it was worth mentioning.