I’m not sure this data’s worth a lot though, as many users (likely most of them) are using anon or throwaway accounts with none to little link to the rest of their activity. Sure it can be processed for statistics but I don’t think there’s a lot to extract further. Reddit is no facebook where the average joe has its “average joe” account, and I don’t think signing up with a google/apple/whatever account is the most common practice on reddit (or at least with your real, non-portmanteau anon account).
As for archived posts and comments they’re already publicly available on archive sites. Why would anyone buy them?
Reddit does not really have a reputation of fair-play. As you have deleted your account without deleting your data you might find it restored with a dummy handle “for consistency”.
My advice to anyone: if you want to take your data back from reddit you should first edit your posts (to some “lorem ipsum suck fpez” gibberish) then delete them using tools like power delete suite or shreddit.
Then you should keep your account alive and regularly pay reddit a visit just to see if its content hasn’t been restored. If you’re in a country under GDPR regulation you can also ask for a GDPR archive of your data that should cover whatever they have on you including posts and comment. This is a good way of verifying what you deleted was actually deleted and not just “marked as” and yet available.
I have left reddit. As in, I do not engage further than discussing migration issues. But I keep an eye on my account and will do so until I’m sure it’s been thoroughly cleaned up. Account deletion is not yet in order, it might be before they go public because I also want them to fall hard from that.