You're on the right track linking cupidity with Cupid, the Roman god of love and beauty — but you need to take away the hearts, flowers, and harp music. Cupidity
is a noun with a negative connotation and means an intense desire for wealth; it's similar to avarice, greed, and covetousness.
In The Count of Monte Cristo, Caderousse — one of the count's enemies — hopes to sell a huge diamond to a jeweler whom Caderousse later murders:
"Let me see this diamond again," [said] the jeweller; "the first time, you are often mistaken as to the value of a stone." Caderousse took from his pocket a small case of black shagreen, opened, and gave it to the jeweller. At the sight of the diamond, which was as large as a hazel-nut, his eyes sparkled with cupidity.