Jabes - I know you're looking to buy used, but I hope you go off to your local music store and play a Martin acoustic bass. This is a beautiful guitar - it produces a warm, bright sound that can stand up to all the other acoustoc instruments. If you sit and jam with others "unplugged" it is the only bass guitar I've ever heard that can stand on its own, without amplification.

You may be able to find one on the used market, by now. I hope you give it a try. I am sure you'll be impressed, and it may make you reconsider your goals for a new bass!