The grade goes on your record, though. The time investment to complete the course with a satisfactory grade would negate the time I have to read the material.
Auditing classes, when allowed, gives you access to everything being enrolled typically does, for the same cost, without any grade associated with it.
And your academic "record" only matters if you plan on getting additional advanced degrees in the future. If you have a degree or two already you lose nothing by having a half-dozen Fs from community college classes a decade later.
And that's only if someone found out you were enrolled in that community college in the first place. Unless you're applying at, maybe, the NSA, no HR department is going to call around to all the local schools to see if perchance you took a class there.
You can check with your local CC if being enrolled is even required. The one near me lets you register as a "community patron" (for free, I believe) with limited borrowing privileges if you live in the area.
Pricing for academic materials is nonsensical, but you can usually find a way to get free or cheap access as an individual learner if you go through libraries.
