The supplies were very minimal, purchased for around $115 from Home Depot:
Six 4" x 4" posts. These came in 8-foot lengths. We trimmed them to 7 feet.
Four 2" x 8" boards, also in 8 foot lengths. We cut 3 of them in half to get six 48-inch long boards.
A pound of 3-inch deck screws. This wasn't quite enough, but luckily we already had some of the same size deck screws on hand.
Two 36" lengths of steel plumbers' pipe for the safety bars. The pipe says 7/8" for the diameter, but that's the inside. It's 1 1/8" diameter when measured around the outside.
Two 7-inch bolts with washers and nuts - these are the pegs for the weight bar to rest on.