Originally posted by DSims $550 was an unusually high price which briefly appeared when a few New Old Stock FA20-35s were found.
No, that price was fixed for quite a while
(I'd been tracking it, before deciding to wait for the DA Ltd zoom).
It was a much lower price than the USD 850
being asked on the Pentax-Ricoh Japanese webstore
right up until later in 2013.
More realistically, for the Japanese market, the last review (9/25/13) of the lens here
SMC Pentax-FA 20-35mm F4 AL Reviews - FA Zoom Lenses - Pentax Lens Reviews & Lens Database
states: "So if you want, you can get it new for about [USD] 500 as of this moment, but of course no USA warranty will come with it."