If your not listening to the Freakonomics Podcast your missing out on some interesting insight.
This recent episode of Freakonomics Radio was an interesting one about customer service which is what a good freelance editor delivers ontop of the technical and artistic skills. The Social scientist prove what most in our industry almost always fail to appreciate, cost and quality are related.
When I get request for a quote occasionally some potential clients will inquire, "why is your quote and rate higher than.." Then, I explain that it's usually a worst case scenario guestimate, factoring in some contengency time and trying to anticipate some problems that has occured in my past experiences.
About my rate, I use the analogy of a general contractor quoting for some work on your house. "Never use the cheapest quote, that guy is usually the problem/unexperienced craftsmen."
Unfortunatly, sometimes some clients don't take my advice and the outcome is usually not satisfatory and they inquire a few months later with a request for a Fix-this-mess-Quote.
Invest in your post.