What the heck does a noble mind have to do with anything? (Aside from rhyming with unkind and giving this line the feel of an ending.) Rich gifts go sour on any kind of mind if the giver turns into a jerk. If you gave me a car and then turned into an asshole, I’d want to sell that car, stat, no matter whether my mind was noble or not.
But Ophelia uses this “noble mind” phrase at least twice in this scene. This noble mind appears to be hers. The next noble mind is his. Noble minds are clearly important to our girl, Ophelia. And I wonder if this is her value or her father’s. It’s not a phrase I can think of him using, so it may well be her own. The idea of that pleases me – since Ophelia seems to have so little that is truly hers. Even a verbal tic would be a little something.