I am looking for the same.
Example: One Price number field, and if 2 other checkboxes (Free, As agreed) are marked Price number field is hidden and value is cleared.
Difficult to make template code with if, else conditional if for instance both Price number field, and Free checkbox field are both with values.
I guess I could solve it with Select field, 3 options and some conditional to show Number Price field if one option is chosen. But it is very strange setting for average Users (building classifieds site).
