Of great value
It'll make him an invaluable asset.
This work is invaluable as a source for the history and situation of the church in the 2nd century; for it contains nearly the whole of the famous work of Celsus (Abyos angs) against Christianity.
But his experience was invaluable and soon he became prominent in public affairs, a visit which William III.
Fouche, pulling the wires through the police, was an invaluable helper.
They are invaluable to make flags flutter on a still day, when there is no wind.