If the information is useful, leave it up because it is useful and the web needs useful information.

If it is useful and you sell it, it will become less useful.

If it is useful and the cost of keeping it online is onerous, perhaps ask for advice here in this thread.

If it isn’t useful, it doesn’t really matter what you do and there’s nothing wrong with taking a willing and informed buyer’s money for something useless.

Good luck.

[edit] I don’t think “wrapping it up” matters much to your readers. People are used to serial creative work dying if for nothing else but Youtube.

Write a wrap up if you want to write a wrap up. It is ok to just move on.