Stock or after market? Dumb dumb no understando.
I have the cheapest L lens for my 70-200. It's the F/4 version with No Image Stabilisation. Can get one for around £300 or so now I think!
70-300 has more range, but that's about it. the 70-200's are far quicker, have a constant aperture and have far better optics so give far greater image quality. Definitely recommend!
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”