I understand your point. While I like to be able to look at past ads to help determine market value before selling/buying...
Just because an item sold, doesn't mean it sold at the asking price. There's no mechanical means to post the actual selling price like there is on eBay or GunBroker.
...I see how that could be cumbersome to manage and view.
"Cumbersome" doesn't begin to explain the complexities.
Are you volunteering to log-on twice a day and manage that mess ? Dealing with scammers. Finding "members" who haven't logged on in 18 months. Getting cursed at for removing someone's 13 month-old ad. Having to tell people their ads don't meet the CZF specs because THEY didn't bother to read our rules? Then finding a pleasant post in the General Section calling you the "Gestapo" because you had to take one of the above actions.
Cumbersome is not the exact word that comes to mind.