How does these 'all's be parsed?

Question

[nurse, Madam Pomfrey] “And you have another visitor.”
“Oh, good,” said Harry. “Who is it?”
Hagrid sidled through the door as he spoke. As usual when he was indoors, Hagrid looked too big to be allowed. He sat down next to Harry, took one look at him, and burst into tears.
“It’s — all — my — ruddy — fault!”(1) he sobbed, his face in his hands. “I told the evil git how ter get past Fluffy! I told him! It was the only thing he didn’t know, an’ I told him! Yeh could’ve died! All fer a dragon egg!(2) I’ll never drink again! I should be chucked out an’ made ter live as a Muggle!”
(Harry Potter and the Sorcerer's Stone)

‘It’s all my ruddy fault’ seem to be an example of Mr. StoneyB’s explanation. Yet, case (2) is not clear to me. Is it the same case? Or is it a so called verbless clause: ‘all’ is the subject and ‘fer a dragon egg’ is a predicative?

Answer 1

In the second case, all is not used as a determiner/pronoun but as an adverb with the sense of entirely. All fer a dragon egg! is not a 'sentence' but an adverbial phrase which is added to qualify the preceding sentence.

All for X is an ambiguous phrase. Often it has a simple literal meaning: “I did it all for you” means I did it entirely for you, not at all for myself. John Dryden titled his play about Antony and Cleopatra All For Love, or The World Well Lost, which has a pleasing double sense: his heroes acted entirely for love, and they gave up everything for love.

In this case, however, all has an overtone of merely—that is, it implies that what follows is trivial. “You could have died for nothing more important than a dragon egg.” “All for naught” and “All for nothing” have the same interpretation.