I'd probably keep the Steinberger and the jetstar due to their uniqueness.
The Washburn, unless you're very comfortable with it, I'd put up on the trading block along with the Cort bass. (The other one's for your son)
That way, you can up your budget for a bass you're intending to buy. That being said, I would buy a more well rounded bass, the first two are basses that aren't exactly all round basses I'd see playing on a regular basis. A number of factors come into play in deciding your all round bass though, the music you enjoy playing, the size of neck you're looking for are examples. You've got quite a number of possible choices given your price range and especially if you're open to used basses.