Agree with thefixer here, after you bought many items, how do you remember which one you can use commercially? The readme? I've never seen such differenciations in 3D objects, though e-on is pretty inventive in this field....
I think Vue users would want the ability to have the object in the software they use. OBJ doesn't always translate well into Vue, depending on the export options from the original format. I know there won't be any problem with Walli's work, but I doubt he'll be the only merchant.