You have serious reading comprehension problem.
If google pays the contracting firm $75 to $85 per hour, what do you think is the payroll tax, insurance, overhead, contracting firms profit? You are looking at $40 to $50 per hour for the H1-B employee and if the contracting firm guarantees some bench, some paid vacation, god forbids a 401(k) match, you are looking more like $70 to $85 K per year.