According to the FAQ section of the deal page, each code purchased through the AppSumo deal allows you to create 5 websites with full PRO functionality and the ability to link them with custom domains. You can stack up to 10 codes, enabling up to 50 websites. Additionally, you can create unlimited websites with free functionality, which can be published on a brizy.site subdomain but cannot be linked to custom domains. So Tier 1 is 5 websites total per code (not 5 per month).