well, not that expensive, after all

If $6.2 million per day is not expensive then you must be earning a handsome salary.
Besides that, you have forgot to add marketing agencies cost and so the actual figure would be more than this.
Also, there can be n number of ways for advertisement. The possibilities are endless and we just have to be as creative as we can.
So the amount we spend on advertisement can never be calculated because it all depends on one's creative thinking.