I ordered one of these units from a different source ( paid $70 ) and am very happy with it.
The only real complaint I have is that the soldering iron doesn't really fit very well into the holder. Meaning that
the part on the iron that's supposed to fit into the holder doesn't really fit - it's a little too large, and therefor kind
of flops around a little and isn't held firmly.
I don't really care for the default tip that comes with these units ( conical ), but you can get replacement tips
from Hakko-us for about 6 bucks each.
I think that 40 bucks is a great deal!