The Continuum Companion to Leibniz is reviewed at NDPR – the whole review is open access, so will only quote a couple of telling lines:

On the whole, the volume is of exceptional quality. Each and every article represents an exciting, insightful and supremely qualified contribution to current discussions and the volume would very soon occupy a place of honor on the book shelves of a great many early modern philosophy scholars if it wasn’t so insanely expensive. Instead, we must try and beat each other in the race to the nearest library holding a copy.

Yes, £100 or $190 does seem ridiculously priced…