That sucks Ian (about having they guy reject the kit). What a gutless tool that he can't tell you himself and has his wife run interference for him.
For what it's worth, you might consider getting a deposit up front to at least cover the cost of the kit and any accessories. My wife occassionally does custom artwork for people and she always insists on an up-front deposit sufficient to cover the cost of the raw materials (canvas, fabric, paints, whatever). That way if the buyer bolts at the end, at least she is JUST out her time which helps minimize the sting a bit.