Williams 58 and 85's offer the highest value "dollars per watt" & "dollars vs. time" performance in the market today.
 
Cycling Power Lab models cycling performance by applying mathematical/physics models to real world course, weather and component data with the goal of answering many of the performance related questions aspirational bike riders should be asking.  The below reports evaluate properties of Williams Wheel System 58 and 85 versus comparable wheel models from competitors.  This report focuses on:

• Theoretic Time-On-Course savings
• Aerodynamic Value Analysis - Dollars Per Watt
• Aerodynamic Value Analysis - Dollars versus Time-On-Course Saving

Link Here:       http://www.williamscycling.com/Cycling-Power-Lab-Analysis_ep_46.html