The average cost of an HIV rapid test in North America is between 12 and 15 dollars being sold to hospitals, etc. I don't thing it would be that far fetched to say the average cost of these tests would be 20 each. This would equal a total of 3 million a year just in Incidence tests.
Please do not take the 20 dollar per test as the truth, I really don't have any idea. Just speculating.