Pre-sales Question

Hello,

Not sure if this is the right place to ask this question, as I couldn’t find a spot to submit pre-sales questions on the site. I have a question regarding how the licensing is structured. If I purchase an agency license, I get everything listed on the shop page correct? Also, if I decide to upgrade from agency to enterprise license, do I only pay the difference between the two? Or do I have to purchase a separate license?