SpongeBob is taking Gary for a walk. They spot Mr. Krabs in a free parking spot. Gary gets a little spazzy, so Mr. Krabs asks what's wrong. SpongeBob says that's what Gary does when he finds money. Mr. Krabs decides to take Gary to look for spare change all around town to feed his obsession for money. When SpongeBob asks what Mr. Krabs is doing with Gary, he just gives SpongeBob an impossible task (like painting the Krusty Krab with a toothbrush, or rearranging all the wall rivets from largest to smallest).
Mr. Krabs collects money from people at the Krusty Krab, Goo Lagoon, and the Laundromat. He then finds an arcade and goes inside. Mr. Krabs decides to disguise himself and Gary as a pregnant woman. Mr. Krabs tries to take everyone's money, but Gary is so worn out that he can't attract money anymore, as doing so causes him pain. Meanwhile, SpongeBob is finished with his tasks, so he looks for Mr. Krabs, but the guy Mr. Krabs took money from tells SpongeBob that Mr. Krabs and "his snail" have been stealing money. SpongeBob finds Mr. Krabs and is mad at him for putting Gary through all that pain just for money. They begin to argue, but they get distracted as Gary involuntarily starts collecting all of the money in the arcade (even from inside the game machines themselves!) The huge amount of money forms a massive wave of coins, which begin sliding towards all the Bikini Bottomites in an avalanche sort of fashion.
Everyone tries to exit the arcade to avoid being swept away, except for Mr. Krabs, who runs toward the large wave of coins in a fit of money madness and gets literally crushed by them. Mr. Krabs ends up in the hospital. After discussing what happened to Mr. Krabs, SpongeBob asks what caused Gary to begin attracting money. The doctor discovers that he had swallowed SpongeBob's Mermaid Man and Barnacle Boy fridge magnet, which had quite a strong magnetic pull. When the doctor points out the bill to Mr. Krabs, he responds that he doesn't have enough money to make his payment. The doctor corrects him by mentioning that all the change he collected with Gary would cover it, prompting Mr. Krabs to yell "Nooooooooooo!" in defeat as the episode ends.
Mr. Krabs keeps calling Gary by a different name. Also, he mispronounces snail, instead saying that Gary is a "sneagle."
SpongeBob keeps getting impossible jobs to do at the Krusty Krab to keep him busy.
This was originally going to be in Season 8, but this episode was aired in 2010 and cannot be paired with an episode that's in another season because "Gramma's Secret Recipe" is part of Season 7 along with this episode, which means both episodes to be a part of Season 7. Season 8 was moved and aired in 2011. 
This episode reveals that money in Bikini Bottom is magnetic.
This episode reveals that Mr. Krabs can speak at least a little Snail.
The Cent of Money is a pun on "The Scent of Money."
When the scene shows the fish playing the arcade games, one of them has a character and game similar to Pac-Man.
When Mr. Krabs calls Gary "Sneagle", it sounds very similar to a character in The Lord Of The Rings, whom is named, "Smeagol".
One of the games featurs creatures that look and move like the aliens from Space Invaders.
It was impossible for SpongeBob to see the difference of the bolts with a magnifying glass, as he said they are off by nanometers, and just 1 nanometer is 5 atoms long, so SpongeBob would need a microscope to see the difference.