"free" because I had everything on hand already! Starting with the bunk ends - 7 foot span, but I only had 6 foot poles on hand. I also had a metal pole with 9/16" inch inside diameter - it just fits the bamboo poles which are nominally 1/2" (they vary along their length)! So for each bunk, I cut 2 x 40" pieces of bamboo and a 4" sleeve out of the metal to join the 2 poles - spray painted all brown. End caps are chair foot glides. The bamboo has a hollow core and these glides just screwed in easily into 2 of my poles, was too loose in one pole (fixed with a dab of glue), and needed to drill to widen the cavity slightly in one pole. I mounted an eyelet screw and passed a thin bungee loop into it. Easy to take down if needed, and the added benefit of using 2 shorter poles is that they are easily separated and stored for travel if desired, though we left in place.