There's an '81 Acro in a local music store and it's available for $130. Similar shape, it needs a little love.
I would keep shopping...they're so readily available that you should be able to find a private sale, in better shape, perhaps for less.
Yes, the calculator is accurate, but you will sometimes see the weight of an Acrolite listed at "51 pounds" when I can state with some authority that it is 18 pounds in the case with the stand. Other times they will use the "Dimensional Weight"... Whatever the ... that means....
Dimensional weight is the weight that the shipper charges, if a package is exceeding a certain H/W/L.
Example: to ship one of these drums, the dimensions are say 24x24x14, an extra $5-10 may be added for exceeding 60". Despite the package weighing 24 pounds (Acro,case, with packing materials etc.), an extra charge of 25 pounds may be added.
"Brown" for example, has revenue recov. clerks and their responsibility is to find and scan packages who's dimensional weight was not figured in. This cost is billed to, guess who, the shipper. Typical recovery for our group is well into the tens of millions per year, in one facility!
Anyway, didn't mean to hijack the thread...possibly good information for buyers and sellers though.