Problem: How does the sentence end?

Victoria fed the goats in the morning but not Amy because 
Answer: Amy was unfamiliar in animal husbandry.

Problem: How does the sentence end?

Derrick had excellent credit but Christopher did not because 
Answer: Derrick didn't spend beyond their means.

Problem: How does the sentence end?

We add milk to the cake mix, but not egg, since the 
Answer: egg was less important for the flavor we wanted.

Problem: How does the sentence end?

Felicia would make toys for their kids while Samantha would buy them since 
Answer:
Felicia is poorer.