Upgrading my paid account with 50 private repos to say 150 private repos

Hi,
I have a GITHUB company account that has 50 private repos. I pay 100 USD per month in subscription. I want 150 repos in my package. How to get to such a subscription?

When I check the available options, it says I am in “GOLD” and “legacy”. and option to upgrade is in fact “downgrading” to access unlimited repos.

My ask in simple words - need 150 private repos with as much storage as what I have now for each of the 50 private repos. How can I get it in comparable terms?