Running back value in the NFL is low and getting lower - The Washington Post
Why has the running back position become so devalued in recent years in the NFL? - Quora
Measuring NFL Running Back Longevity: Falling Off the 1,800-Carry Cliff
Agent's Take: Are days of high-priced NFL RBs on verge of extinction?
Going over the most paid running backs and it seems to answer itself.
How rising college football head-coaching salaries will force the NFL to adapt or get left behind - ESPN
Who are the richest NFL players?
The Perils Of Salary Cap Imbalance Between Quarterbacks & Running Backs
Investors Eye Profit Rebound After Yearlong Earnings Recession - BNN Bloomberg
Why has the running back position become so devalued in recent years in the NFL? - Quora
Agent's Take: Are days of high-priced NFL RBs on verge of extinction?
Why NFL running backs aren't getting paid like the stars they are