Lets pass a bill to cover the moon with yogurt that will cost $5 trillion today.
-- Paul Ryan
Oops.
The surface area of the moon is 14,658,000 square miles.
There are 4,014,489,600 square inches per square mile.
Therefore there are 58,844,388,556,800,000 square inches of moon surface.
1 lb of yogurt is about 1.5 cups (I just measured the volume of a yogurt container that claimed to have 2 pounds of yogurt in it when it was bought, and divided by 2).
1.5 cups is about 22 cubic inches.
At a depth of one inch 1.5 cups of yogurt covers about 22 square inches. At a depth of 0.1 inch it covers 220 square inches. (I think a 0.1 inch depth is stretching it (heh), but let's be conservative -- it seems appropriate)
So 1 pound of yogurt will cover 220 square inches to a depth of 0.1 inch.
Yogurt in bulk costs somewhere around $1/pound.
It would require 58844388556800000 / 220 pounds of yogurt to cover the
moon to a depth of 0.1 inch.
That's 267,474,493,440,000 pounds of yogurt, give or take a pound, at a cost of
$267,474,493,440,000 -- $267 trillion dollars.
Mr. Ryan, you just estimated that the job could be done for $5 trillion dollars.
In other words, you're off by a factor of 50 just considering the cost of materials!
We haven't even talked about transportation costs: getting the yogurt into lunar orbit and landing it safely on the moon; or labor costs: paying sub-minimum wage (it's a Republican project, remember?) to have it spread out evenly.
No wonder your budget didn't add up.