In the book the metamorphosis can Gregor's death be considered a sacrifice in any sense?
Yes, and no. With your question, you raise another - for whom is his death a sacrifice? Did he sacrifice himself (as a martyr) or did his family sacrifice him?
While The Metamorphosis has many themes running throughout, the idea of liberty is rather prevalent. Could Gregor escape his family and duty? His self-identity seems to deteriorate to the point where he has become something he doesn't want to be - and in the end, he dies, whether from self-loathing, self-sacrifice, or because his family no longer want or need him, or because they have learned to hate his bid for freedom are among the many possible answers.