It was $100 plus $10 shipping to the United States. I did not get instructions either but he did sent 51 photos that shows all the parts as built. The can be seen well as they were cast in tan and the donor kit was green so they stand out and with what can find online, I think one should be all set. I honestly did not worry about as I have had other kits such as this and I was fine.
As for contacting, just send PM from the Facebook page. It may take a day or two, but always got a reply even with asking many questions.