Case When with And statement to look at two values to determine value given

I have a situation where i have the following

Multiple Business Names
Sales Opportunities that have an Opportunity number, but within that Opportunity number there are multiple rows that make up the sum total of that opportunity.

What I want to do is say if the business name = "X" and the total opportunity value is greater than a certain $ value, then call it a "whale".

I have multiple businesses within the same set of data and each business would have it's own threshold for what would be considered a whale, but the key is that I have to add all of the rows related to that opportunity, I can't just use one of the rows.

I feel like this is a case when statement, but struggling to do this where I can take both the name and the total dollar value of the opportunity to come up with the name.

(2) Answers