Learn English – What’s the word that encompasses both creating something and editing it

My first thought when I saw “buying and selling” was trading (independently of coleopterist. The verb trade covers both bartering (trading when both parties put forth goods or services) and buying/selling (trading when one of the parties puts forth money).

In context, this seems to be specifically about evaluating the price. I believe the term generally used in this domain is appraisal; valuation or pricing are used with a similar meaning in other communities.

Scope, as in scope of responsibility, is used to delineate the extent and limit of a person's responsibility or assignment.

scope Syllabification: scope Pronunciation: /skōp/ NOUN

1. The extent of the area or subject matter that something deals with or to which it is relevant: we widened the scope of our investigation such questions go well beyond the scope of this book.
2. The opportunity or possibility to do or deal with something: the scope for major change is always limited by political realities

http://www.oxforddictionaries.com/us/definition/american_english/scope