Below sentence is a conversation of Hermione in Harry Potter and the Chamber of Secret.
Slytherin lead: A gift from Draco's father.
Draco: You see, Weasley, unlike some, my father can afford the best.
Hermione: At least no one on the Gryffindor team had "to buy their way in". They got in on pure talent.
Draco: No one asked your opinion, you filthy little Mudblood.
What is the role of in on?
Does it mean the same as
They got pure talent.
In addition to that what is the meaning of the phrase "to buy their way in"
I know conversation differs from the grammar. Is it possible to use the same in written form? It would be more helpful if someone explains this with examples.
Note: Additional information has been added, and one more question is also raised.