Because they have to be machined to very precise standards.
Originally Posted by Allen Bookout
As to answer the original question, well I would go for the LN #140. It too is pricey but with the skewed blade and fence, it would be a very versatile plane to have in ones arsenal. At the same time, if you like doing stuff by hand instead of a machine, perhaps a LN Router Plane might be good for you.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"