Being a specialist can make you more expensive. But job opportunities requiring that high level will be limited, both in their numbers and geographically.
Being a generalist perhaps pays less but opens a wide variety of job opportunities to you, potentially around the world.
Also for higher level and managerial jobs it is preferred to have a person experienced in a variety of things, techniques and technologies. Knowing edges and being able to see a big picture makes you a valuable asset.
A few of my ideas on the matter: Going specialist or generalist