That pit we hunted would be very easy and cheap to build yourself (If the water table would allow it). If were setting one up on my own land and not needing to dig up a pit to move it, I would do the concretet wall pit. Dig a hole, drop your form in, secure it and pour. The geese were so close to us Hogman said he was scoping out their boot holes
. Something wrong with that hogman guy. They could not see us at all. The roll top was perfect.