Understanding the Gemini API Billing Structure: Free Usage vs. Paid Tier

As I delve deeper into utilizing the Gemini API, I’m contemplating the transition to a paid billing tier. This decision is driven by the impending discontinuation of access to the pro models for free tier users.

To clarify my approach, I have a couple of important questions regarding the billing structure:

1. Continued Free Usage: When I enable billing for the Gemini API, does the paid tier still incorporate any free usage allowance? Specifically, am I able to use features that remain within the free tier rate limit without incurring charges, or does enabling billing mean that all usage immediately becomes billable?

2. Billing Implications: I would like to understand if there are thresholds in the paid tier where I still benefit from a free tier ecosystem before any charges apply.

Understanding these key aspects will help me make an informed choice about whether to switch to a paid tier. If anyone has insights or experiences regarding this billing structure, your input would be greatly appreciated!