This is surely a scam. Pay in advance, wait maybe 5 months to get the product, and no guarantee. It looks like they don't take credit cards, which could be reversed if the product doesn't meet the basic test of merchantability (do what is supposed to do.) One of the biggest scams is to provide a money-back guarantee. Even if the product totally sucks, not everyone will bother to return it. They don't even do that.
And the testimonials are laughable. Ok, someone spent all that money on a mail order product, and forgot about it, in their garage for months? Yeah right, that happens alot.