Enriquecerse a costa de los demás

[ROBINDESBOIS]

How do we say it in E?
To enrich onself on othe’ s ?

[Rusty]

Get rich off of (someone else) others
Enrich oneself off of (someone else) others

[poli]

..also, and I like this one more, to enrich oneself at the expense of others

[ROBINDESBOIS]

a expensas de los demás, I heard that one before.