If I remember rightly it took me about three and a bit years to become legendary under the old system which was of course a bunch simpler. All you had to do was shitpost for long enough without getting nuked.

Probably by the end of the year I'll have earned 1000 merits and the system was introduced in January 2018 so that's two or so years. I wouldn't exactly class myself as a quality poster but I try not to spout totally mindless shit. If I can do it then any old donkey can. All it takes is some alertness, interest and self awareness.

If it's an aim to do it from scratch for better or worse there are areas of this forum where you won't get enough merit no matter how good a poster you are. Alts is obviously the biggest merit desert as few users have any merit of their own to give away.

Meta appears to be where the merit rains. I'm not completely sure why.

As for buying an account, people are getting ever more vigilant about this and as it's so much harder to rank up they're more protective about any old asshole waltzing straight into a sold legendary account. I personally wouldn't ever feel totally at ease with an account like that. You never know when someone will unearth you.