Why not keep everything stationary and do something like this? You'd have two chicken doors (one on each side) and for one year you let them do their thang on one side, the next year you switch. In the middle, between the garden/run areas is a place for composting. This is exactly the idea that started me on this track .... But I have to have multiple pens.And then they blame everybody in the house for not putting things back where they got them... except of course, you know who. That's when I turn the box over and let everything gently slide out. Sometimes you have to shake them a little but they generally slide out fairly easily. You are exactly right. As a service tech I've had to unpack and install HUNDREDS of PCs Monitors and Printers. You can also look up alibris.com They have used books and many times, their prices are better than Amazon, sometimes not. It's worth looking for though.