At the time I think i payed £12 per barrel,drilled a few drainage holes,piece of ply inside on 2 pieces of roofing batten,so any condensation runs under and out,fill with your bedding of choice?made a frame out of 2 x 2 timber,to fix the barrel to the wall and so you can hose under it,bit of ply on top with some carpet stuck on with some contact adhesive.... cheap option if you got chewers??