Final answer:
TechnoGeek has a competitive advantage of $500 over VarsityBlue.
Step-by-step explanation:
In this scenario, TechnoGeek generates $900 of economic value per sale, while VarsityBlue generates $400 per sale. The difference between the economic value generated by TechnoGeek and VarsityBlue is $500. Therefore, TechnoGeek has a competitive advantage of $500 over VarsityBlue.