It was meant to be heavy, to absorb the quite stout recoil of 10ga magnum shells in a fixed breech gun. Price in the 1961 Stoeger catalog was the same as a Bernardelli Roma 4, which today--depending on condition, and in 12ga--would be about a $1500-2000 gun. Would be interesting to see some current prices on Thunderbirds to compare. They're not all that common, but then again, I don't know that you'd want to shoot steel shot through them, which makes them of less interest to waterfowlers--unless maybe Bismuth is available in 10ga. Tungsten Matrix is not. Otherwise, you're talking a real heavy turkey gun.
