Hi from Mountlake Terrace. We designed our own and it cost $300 to build with no reused items. I went 2x3s to keep weight down and my brother went 2x4s since he reused a ton. His cost less but was a pain to move. Check out my blog for details. Sorry I don't know about that design but check out CList and Freecycle for repurposed items. Let me know how I can help by commenting on my blog. Been there and done that and all. Good luck and welcome!