I've seen restored mid number sandys sell for 13 to 22K recently. As you know the parts are cashy. I'd make a quick list of what it needs and make sure it's got it's own motor too, then do the math.
It depends if you want a big project. I was lucky, mine was very complete, very original and priced right.
I've been riding my sandy find but recently I consider the miles and take the 76 out instead. I recently turned it over to 9K, one with more miles I wouldn't worry so much.