If I wanted to get to 5 million relevant followers…

If I owned a beauty brand and I wanted to get to 5 million relevant followers who might potentially be interested in the brand and its lifestyle….

What would you do…based on a:

1) low budget
2) medium budget
3) high budget

(And in a realistic time frame)

This is purely hypothetical but I am keenly interested to see what people say it takes to get to these large numbers.