It’s the economy.
I have been in the market looking for a ti for some time now, and I would consider your car a deal at $4,000, I would pay that. $5,000 is reasonable for a 1999. Roll the
“Time Machine” back just 6 months to December 2008 and I saw cars like yours selling easily for $6,000-$6,500 and they would only last days before they sold.
In fact, a member on the org sent me a heads up on your Craigslist ad before I saw this post and I could not believe that it was not sold either.
Bottom line though is that something is only worth what someone will pay you for it…
Good Luck with the sale