Don't forget Stolze does the Ransom model, which is similar in style, but different in scope (once a project has been ransomed, he then releases it for free to everyone)
One thing though, is that they work because the respective authors have been around a long time, and have a lot of name-recognition, credits as designers, fanboi's, etc.
I honestly don't know who you are, so I am a lot more leery about signing up for anything. Once you get some previews out, then I'll take a look and maybe do it.
Hope that helps!