Verify rate limits

Similar to #16 I want to validate that we are not going to be blocked by the default rate limiting which I think is very low — do we have a GPT-4 key that has a reasonable rate limit associated? 

I have a GPT-4 key but it has a $200 limit and I need to manually request increase, it's ambiguous what the result would be.

@gutelius do you have a key and can you check what the limit is on it?