Upgrade to zoom one Business

[Lackermeier]

I currently have the zoom one Pro package (EUR 189.00 per year) and would like to organize a meeting with 150 participants next week. Do I have to buy an upgrade for EUR 1899.00 just because only 10 licenses have to be booked at once with the zoom one business? Is there a cheap way to upgrade or do I have to cancel zoom and switch to another system?

[PSC1]

My question is based on a similar issue - we have a Pro licence ($209 AUD per user) but need to upgrade to host a meeting of over 100 ppl. We only have 2 users, and can't afford to pay $70 per year extra for both users to upgrade when we only need one to host the meeting - can I upgrade one user from the Pro plan to the Business plan and keep the other user on the Pro plan? I've looked everywhere & tried getting help from the chat but can't find any useful information.