They are often worth it, your machine has some nice stitch patterns. I would go over the oil points, take the top and throat plate off. Part of the casing around the free arm probably comes off too. Turn the hand wheel by hand, inspect gears carefully for lint, piece of thread, piece of broken needle, etc. Sometimes plastic gears can crack, on a good model they are well worth replacing. Ceck belts if there are any. With a bit of luck, cleaning and oiling is all you need to get it going again.