He could buy both, cool down and clean up his act.
As an aside for those following along at home, here's my thinking on these threads: the For Sale category was started a fair while ago as a place for regulars, contributing to the community over the years, to get some help selling their car or whatever else. The OP here is one of those regulars who has been a valuable contributor. Over time, there have been some less-than-regulars or outsiders taking advantage of it, but it's hard to assess every post like that. Perhaps someone has no known alias, but has been reading for years - it's not always easy to tell.
Now, 'For Sale' posts should absolutely not take over the forum and I'd really prefer them to not carry the same "weight" in the index as a regular basketball topic. But filtering them out means they're largely useless to regulars using them - who's going to check the For Sale category regularly to see if there's anything new? Show them in the index but as a different colour or smaller font (have tried that before) and they actually stand out more.
I'm happy to hear suggestions about all of this. One idea I had was to filter them from the forum index, but show a little count (e.g., For Sale (2)) of recent posts beside the category name so users had a visual cue, but without having to click in to browse if they weren't interested.