Guessing dimensions comparing the lady next to it and the guns on it, i'd say the finished product is about 5 ft tall. Gaps between guns looks too long, close the gaps to possibly have room for a third set of pegs on either side, letting the stand hold 6 guns instead of 4. The ladder part itself is about 1 ft wide, but i'd go with a little more narrow cuz many guns are relatively shorter now. The base is wider than the ladder, mostly cuz the pipe joints make it so, but also helps keep it from tipping over.
Try this as a collapsible version of the pyramid, starting from the top down:
Pyramid Point - wouldn't pe pointy, really. Two T joints with a 10" pipe connecting the middles, and four 2" pipes connecting 2 pairs of hinge joints with four 12" pipes coming down. Joints may not be pvc but they exist cuz i see them on chain link fences. The T joints separating the hinges would allow the assembled pyramid sides to fold together. Most complicated part, i promise. Even more complicated if the hinge joints aren't real, lol!
Top Hangers - top pipes come down to two 4-way joints, with a 10" pipe connecting them, and a pair of 5" or 6" pipes sticking out. Or, if you want the pipes to swing in for storage, copy the doubled-up T joints shown in the pics above, although 4-way joints would be more stable. Have two 12" pipes stick down for next level. Repeat for other side.
Middle Hangers - repeat.
Bottom Hangers - repeat.
Pyramid Base - one side with a pair of T joints, middle joints point up to meet Bottom Hanger legs, a 10" pipe connecting the inside joints, and 4+" pipes (the longer, the more stable) on the outside joints, leading to a pair of L joints. L joints then connect to long pipes, the lengths depending on however deep you want to make the base. Then the long pipes lead to a duplicate arrangement for the other side of the pyramid, except maybe you can cut a sort of cup into those L joints so the long pipes can snap into place, then unsnap when you want to fold the thing up.
I'm going out to eat tonight, i expect a long wait at the restaurant, i'll draw up some specs on a napkin. Anyone wants copies of my blueprints, paypal me a dollar.