How could any gem that size even low quality be worth "a couple hundred bucks"? Or rather, how can the range in value be so insanely large?
Also, like many other gems, the price of a gem varies wildly with its clarity, etc.
So the worst case scenario,I suppose, is that it could be that the stone is only worth its weight as rock dust. But generally I agree with you that it seems unlikely, and it's probably just hyperbole.
"On the packing slip he wrote “rocha: rochedo—rock” and listed the value at $100."