It looks to be CNC cut parts, whether laser or waterjet, doesn't matter. But it's not designed around any particular components installation, and that will determine how much cutting & whacking you'll have to do to get it working.
The excavator itself is not going to lift 80lbs, but rather that may be the force the cyls are capable of at their maxium pressure... although they look like in the pics to be generic air cyls... so one might as well build their own so they look & function more prototypical and the fittings be in the correct locations.
$1500 is not a bad starting point, the hard part of CAD & laser cut parts is done.
I see on their site that they are considering to design a front shovel & I would certainly be interested in buying a shell of that model.
