MTOW about 400 tonnes, scaling weight by volume you'd get a scale weight of 134 grammes, or about 5 oz. Probably not too far off the actual model weight.
Hard to know what to scale cost by; if you also use volume that $40 equates to about $120 million. Which is about half the list cost for a new -400, I believe. So to scale the cost by volume, it would be 1:180 or so.