Usability investment costs are easy to measure, yet the usability benefit estimations require many critical assumptions. Slight changes in these assumptions impact the economic analysis significantly. This paper provides preliminary work and implications on how a decision tool could be developed that would optimize the usability benefit assumptions. It incorporates Meta Analysis, regression analysis, goal programming optimization, simulation, quantile regression, and economic analysis to model cost justification of usability. The key results indicated significant positive correlation between sales and traffic rate, and error rate and task time. The outcome is a decision tool for usability investments.