blades vrs cast, steel shafts vrs graphite?

given any width on the course from a straight line, are either of the two options more acturate than the other? or is it all in the player?
i raised this as a pro shop person told me graphite shafts are much more acturate, "thats why they are so expensive"? believe it or not. if so, does the same argument involve blades vrs cast irons?

as an example, i use to wind surf, when started i was sold very large boards, withine a month i out grew them and moved on to smaller faster, more unstable boards, but once you could control them they were outstanding. eventually my garage filled up with five sets of boards. in retrospect, i feel i could have skipped some of the boards and gone straight to the final one with the same results, it would have ment more physcial effort and conscientration, but i would have save thousands of dollars.

thanks

pat