It depends on how you build it.
Most summer setup drop ins are made by teenagers raiding their Dads tool shed and going nuts. Thus, an over-built permanent structure is made.
I'm sure that if you make a 6' tall drop in and put good thought into making it mobile, you could move it yourself, or at least move it with a friend.
Sorry that's all I can give you, but I don't think you can expect pound measurements out of NS.
But When I Came Back,
They Didn't Have No Grapes!