This is also a great site! I remember there was a similar one but for "open source" (heavy quotes) self-hosted software. I find those sooo shady. I also remember there was some Nginx proxy or similar that enabled SSO in several of those applications.
Happy to answer any other questions you have around price or Vendr in general. If you create a free account, we're also happy to provide a free Premium Onboarding session to help you understand everything about the product. Feel free to email me if you have any other Qs :) emily dot regenold @ vendr dot com