I would go for the double optin. Don;t waist too much time on this one. Just create a landingpage and give away a free thing about your product. Than educate them about the topic and show thema trick or tool to use. When you have done that your prospects will buy easier and faster. Now present your product.
I don't think that you will lose money. Listen, there will alwasy be people who don't like or nee what you have. You can't force them to give you their money. Focus on how to create your product and message in a way that prospects have the feeling that they want and need it.