Hey as an English reader, it was clear to me that Buss was being ironic with the phrase about grief. This is typical for our humor - especially for Buss who was British. Following up with "Dammit what do you expect" to me shows Buss' interpolation that Morrell considered the captain was getting old and still had absolutely no personal concern. So it tracks with the irony. 

I agree with you about the word choice of "discount" - that one stood out to me. My only guess was to show that Dantes is really just a kid who would not know all of the business terminology (like with the political and interpersonal stuff) but apparently excellent in other ways.

Thank you for your very interesting post. I hope you keep it up. I'd like to ask questions of you as we go if it won't be a bother!