I purchased a Babylock Tiara 1 (Same as the original Sweet Sixteen, but branded as a Babylock) about 4 years ago off of Craig's List. Very lightly used, included the stitch regulator and bobbin winder and she tossed in a bunch of rulers. The lady was moving so needed to sell it quickly and was asking 3k for it. I ended up getting it for $2500.00 as I told her I would pay cash and pick it up immediately. That will give you some idea of what I paid for one.
I would advertise it on Craig's List, LongArm University and FB Marketplace. Be sure to comment whether the buyer has to dismantle it and move it to their vehicle. That way, they will know to bring someone with them. Mention how you want to be paid, (cash only, e transfer, whatever.)
I know that the fact that this seller said the machine was set up and available to be tried out was a big selling point for me, as I was driving from Canada to NY state to buy it and I at least knew it was working, if she was offering a trial on the spot.
Be careful about having people in your house and be sure to have someone with you when you do. This lady was elderly and my husband and I showed up and there was no one there but her. I (gently) gave her heck for not being more careful.
Watson