The Great Gatsby, agonizingly aware of the easy money

I'd like to know if "easy money" in this excerpt from the chapter Three of The Great Gatsby means "money that people (not young Englishmen) got without having to work very hard for it or rather "money that young Englishmen could get without having to work very hard for it". Why are they "agonizingly aware"?

I was immediately struck by the number of young Englishmen dotted about; all well dressed, all looking a little hungry and all talking in low earnest voices to solid and prosperous Americans. I was sure that they were selling something: bonds or insurance or automobiles. They were at least agonizingly aware of the easy money in the vicinity and convinced that it was theirs for a few words in the right key.

Thank you.