Last night I picked 3 free doors and a free window frame without glass. My wife saw them posted on Free-cycle. I'll use one of the doors for the dome and Have offered one of the others to a friend for a door for his treehouse. I'll post some pics of them this weekend.
Last week I picked up a 30 inch length of 3 inch I.D. PVC pipe at a construction site. This is the size I am using for the "hubs" of the triangles. I should get another 8 to 10 of these out of this piece.
Also I picked up a light fixture at a garage sale today. A whopping 3 dollars. So far, other than gas this is the most I have spent on the whole project. Tomorrow my wife and I will hit a few more garage and yard sales to see what else I can find for cheap or free.
Total cost so far $0.00