Cheaper meh? -_-"... I think I'd price it equally between them. FA24 has AF, Sammy don't. But Sammy is new, FA24 is not. Sammy is larger, but FA24 is smaller in comparison. Sammy costs $960 new, FA24 costs ~$900 2nd hand.
Haha! Somewhat same price level in a way if you think of its pros and cons..
FA24/2 is much cheaper than $900+ from a proper seller. AF, contrasty and nice bokeh (ie. not so common on WA lenses)
AF is useful if you intend to use 24mm as a walk about lens and esp so at large apertures.