Lock #4 Question:

What could the main idea be if the supporting details were:

1. "Barbie" isn't Barbie's real name. Her full name is 
     Barbara Millicent Roberts.

2. Another fun fact about Barbie is that the first Barbie
    doll sold for $3.00.

3. Additionally, older Barbie dolls that have been kept
    perfect for years can be worth as much as
    $25,000.