"F. Scott Fitzgerald uses his novel The Great Gatsby as a way to compare old and new money and to illustrate the lack of morals in those with old money. The main character, Jay Gatsby, representing Fitzgerald's personification of new money, makes his living selling alcohol illegally. He earns his money quickly and is now showing it off with fabulous parties in his oversized mansion in West Egg. Another character, Tom Buchanan, represents old money being the "scion of those ruthless generations who raised up the great American fortunes." Both act out their dreams. Gatsby's is to get Daisy while Tom's is to completely possess Daisy as well as to appear as a well-rounded intellectual. Tom and others in his class inherited their money and live elegantly in East Egg."(http://www.bookrags.com/essay-2004/5/15/141559/670)
This shows how old money makes people used to it. It's not out of the ordinary and its a comfortable place to be. Tom isnt completely "happy" however, he feels he must also commit adultery to satisfy himself. That is, until Myrtle gets killed. Gatsby is new to money and he wants to show it off. This also makes people suspicious on how he got his money so fast. He too is not completely satisfied with his life. This is where Daisy comes in. She seems to make both sides happy in different ways. Tom loves Daisy but feels he needs Myrtle too and Gatsby wants Daisy all for himself. It seems that no matter which side you come from, you're always wanting more.