There was always the chance that Horrock might say something quite invaluable at the right moment.
Mr. Tucker was invaluable in their walk; and perhaps Mr. Casaubon had not been without foresight on this head, the curate being able to answer all Dorothea’s questions about the villagers and the other parishioners.
Ladislaw has been invaluable, most satisfactory.
The respect was not diminished when Naumann, after drawing Will aside for a moment and looking, first at a large canvas, then at Mr. Casaubon, came forward again and said— "My friend Ladislaw thinks you will pardon me, sir, if I say that a sketch of your head would be invaluable to me for the St. Thomas Aquinas in my picture there.
There are no more uses of "invaluable" in the book.