FIRST released the
Team Drawings that show simpler ways to build the field elements. Like Deetman said, though, I'm not sure how well the pyramid will hold up. The design calls for the brackets on the corners to be 3/4" plywood and U-Bolts.
I'm really unsure as to where to store these things once we build them. The goals and feeder shouldn't be difficult to make and store, but finding somewhere to keep a pyramid, or designing a collapsible one, might be challenging.