Part II, chapter 7, gives us the details of their money arrangements.
However awful the topic, it is impossible not to feel admiration for the style here, the crazy humour, and at times the sophistication.
Then, something else I had forgotten about: Humbert steals back most of the money from Dolores afterwards.
So, while he insists so much on the money she demands, she is presented as having control over him to some extent. But as he is being particularly careful that she never has enough money to leave, he is the one who mostly controls the situation.