How many credits would I need to find low fruit keywords?

It really depends on the seed keyword and how competitive the topic is.

A typical wildcard search may generate between 100 and 300 keyword ideas, which could cost between $0.5 and $1.5 to analyze on the high 50,000 credits plan.

Analyzing all the SERPs would cost between $0.5 and $1.5 (on the high 50,000 credits plan).

Of these keyword ideas, between 5% and 90%, may be considered "low fruit" keywords.

On the other hand, a broader search such as "fat loss" or "car" could generate up to 2,000 to 3,000 keyword ideas, which would cost between $10 and $15 to analyze on the high 50,000 credits plan.

In general, it's usually more cost-effective to use narrower seed keywords for your searches, unless you want to get a comprehensive overview of the competition in a particular niche.