From what I have seen in some areas there is an abundance of used Glock 22s, some of which I am guessing are police trade ins. I would guess that, depending on the area, with some shopping around one ought to be able to find a used G22 for less than $400
http://www.gunbroker.com/Auction/SearchResults.aspx
While used does not seem to qualify for the blue label price, in my limited little world, used Glock 22s seem to be the only Glock lately that can be had for less than the $398 price of a new one.