Too bad I'm not in your neck of the woods... I would take that Subaru off your hands today!
As for new vs. used, if you can find a used van that is of a model year that has high marks in the area of reliability and maintenance and a great price, that would be the way I would go. The hit on buying new would be the deciding factor for me. The Hyundai I currently drive is a 2013 that was $25G new, but at only two years old, I bought it for $16G, quite a difference.
As for trading vs. selling your Subaru yourself, there is a third option possibly. Are there any car consignment lots where you live? They work similarly to furniture consignment stores. You take the vehicle you want to sell to them, they evaluate it, you and they agree on the price you'd like to get, they do the showing and selling of the vehicle and then cut you a check, less their share for their services. I've never done it myself, but hear it's not a bad deal.
Yesterday I was clever, so I wanted to change the world. Today I am wise, so I am changing myself.
-Rumi