So I have to pay $39.96 to access the application and download it into my Amiga 1200 to then use the application itself to browse and buy software online through the apps and see what new apps and games are available for me in my A1200?
There is no "application", it's just a website. And there are no devs that are ever going to use "Project Metropolis".
The yearly fee of 40 USD would have to be paid by the developer, for the privilege to have his software listed on said website. You, as a customer, would only pay for applications you purchase.
But you really don't need get interested in any details. Project Metropolis is just another excuse to create 'press releases'.