I'm not a big fan of the Open Design methodology. The idea of funding the development of products through pre-sponsorship or a ransom system makes perfect sense to me. But the "exclusive, limited time offer" approach of the products leaves me cold.
I did participate in one of these. The final quality of the product was significantly underwhelming for the price. The content was great, but it was significantly over-priced.
The theory seems to be that you're paying extra in order to participate in the creation process, allowing you to tweak the product to your personal tastes. But (a) it's not like you're actually dictating anything, so you'll probably still end up needing to customize the product; (b) the actual amount of influence ANY of the sponsors has appears to be incredibly minor; and (c) even if the sponsors did have meaningful input, do you really want a product created by committee?
If you like the idea of paying premium in order to get access to beta testing, though, this might be worthwhile.
With all that being said, these modules (except for the very first one) are available. However, you have to be a patron of the current project:
http://www.koboldquarterly.com/k/faq