So the asking is down to $30,000 from $50,000.
If you're chasing one badly, you might be able to negotiate a deal as the price seems to be flexible.
I've seen much, much better and far more desirable HQ Sandman Van's (I.E: L31/M21) in need of restoration sell for around $20,000

Still, if you save this one and make it good. You'll still have a rare HQ Sandman, although you'd want to make 100% sure it is what they claim it to be and check the car from top to toe.
Because you will have to throw in access of $30,000 at it to make it right. (Depending on your own skills).