Very nice job Jon. Your GH look exactly like the mine except mine is outlined in green. Mine cost $599.
Jon, what did you put down as your base and floor? For my base, I used 4x4 pressure treated timber overlayed with 10mil plastic. For my floor, I used 4 inches of gravel, sand, and 12 inch concrete pavers. I think I spent around $500 bucks for the base and floor but it is well worth it! You will enjoy your GH!