I haven't heard of anyone using generators as a CTB method but obviously there's lots of accidental cases of such. Provided you live in a private home or do it when no one else is around and you're buying an older generator that doesn't have a CO shutoff, which it sounds like you've found for a decent price, it should be incredibly easy as they put out far more than enough CO.
I've considered this back when I was on this site a couple years ago as I lived, and still live, at home and am unaware of where to carry out the charcoal method without harming others, although I haven't researched that a whole bunch to see if there's a better way to do it. Just the fact that there's smoke and IDK if it will generate enough CO, I've heard stories of several people coming back from it. And, I don't know how I'd go about ordering the necessary items without my parents noticing, as I don't go out by myself and I rarely pay for stuff either, so it'd look suspicious and I'd have to convince them somehow for some practical reason to buy what is needed for this method.
But when I began my research again fairly recently generators originally sounded like a far better option to me, just seeing as the older ones that ain't safety approved or turn off after detecting too much CO are a great choice for this method. Not to mention I have a decent practical excuse in mind to convince them to buy a generator. Although hearing about how much noise they produce wards me off heavily and as there's virtually always at least one person in the house at all times it would take quite some time before I'd find the chance to safely carry out this method.