 Why did Harvey and Joe have such a large tab and the bar that was ran by Johnson?
When Harvey staggered pontifically into the battered metalloy saloon—the only one on Planetoid 42—his tall, gangling partner was already stumbling out, mouthing something incoherent. "Friend," said Harvey, taking out a wallet and counting off eight five-bucko bills, "here is your money. Then Johnson rubbed his thumb on his index finger and wetted his lips expectantly. "Now do you see, my hot-tempered colleague?" said Harvey as he and Joe picked up buckets that hung on the tank. "Johnson, as I saw instantly, is the victim of a difficult environment, and must charge accordingly." "Just the same," Joe griped, "paying for water isn't something you can get used to in ten minutes."
 They were unaware of the cost of the water served by the bartender.
 They were unaware of the cost of the water served by the bartender.  They had consumed multiple alcoholic beverages and lost track of how much they had ordered.  Their funds were unlimited and they ordered rounds of drinks for everyone in the bar, including Genius, who had more hands to hold more drinks.  Johnson had over-priced the alcoholic drinks they ordered once he knew they were drunk.