It really varies between areas.

The blue book “private party” is a good basic guide; I found that Edmunds is more accurate.
An even better guide is the average price asked for in your area.

The Civic is a car that keeps it value, a good condition low mileage 94 Civic can easily be ~4000$, so a Del Sol can certainly be a bit more....

In this specific case 5000$ is a stretch because of the high mileage, but again, it depends on the area….