That's not what the poster meant. It wasn't counting rockets, but the fact that the cost was spread out over multiple years.
Yes, if it were possible to go from zero to moon in one year then that would be all of Google revenue. But spread over 10 years that's just 10% per year.
The parent comment's point is that the money spent on the space program was likely very highly weighted to the first years building that first rocket. So dividing by 10 because it was roughly a decade is probably underestimating the budget needed to get to the moon.
