There appears to be a Bitcoin payment method but only if you buy a year in advance. https://pro.gab.com/upgrade
(Also now that I look at it, there's apparently a bug on the page that will let you go back and select One Month after you select Bitcoin - so maybe that works too.)
Might be possible to circumvent using gift cards paid with cash (or with cash directly). Hard to blame Torba for wanting to sustain the service though
There appears to be a Bitcoin payment method but only if you buy a year in advance. https://pro.gab.com/upgrade
(Also now that I look at it, there's apparently a bug on the page that will let you go back and select One Month after you select Bitcoin - so maybe that works too.)