It really is sad that it has come to this when you think about it. I have to admit that reading about other fellow hobby builders who have been fleeced but unsavoury shops/suppliers has made all of us a bit gun shy of getting taken. After reading so many guys screaming for help on different forums I've changed my buying habits. Living in Canada we are use to having to pay more for parts and when I see some of the deals south of the boarder I feel like jumping on them but at the end of the day I can't afford to lose my money to a supplier who takes my money and runs.
Now a days I deal locally or if I'm ordering something I tend to stick to bigger companies, like TCI or Detroit Speed direct. It's been said multiple times and I have to agree go with someone local and where you are able to follow up personally and ensure you are getting what you pay for. I don't think it's a bad idea having a schedule laid out on when you get your product and payments at certain completion points so that you feel secure and are able to see your product with your own eyes at those completion points.
Now I've got to go read your thread to see what a $40K engine is goin in.