It isn't a particularly good deal IMO with a lot of chances for something to escalate costs (haze) or decrease value (Schneideritis). Based on the above figures, even if it were perfect and the glass didn't need cleaning or you did it yourself, and made a paper aperture scale you'd still have $575 in it ($325+$250). If it has Schneideritis you might find it hard to get this for it if you ever wanted to sell. I'd be willing to spend another $75 - $150 to get a clean one with no issues from a known dealer like Quality Camera or Midwest. In general, very clean ones in late black shutters from knowledgeable and reputable people (not implying that the seller isn't) are running about $750 in shutter, and if you shop around you could get one for around $650, as I did. Mine's very near mint but had Nikon caps so I think that's worth a hundred.
My comments were based on my experience with a similar lens that also had haze (besides the Schneideritis).
It may be fine but it sounds like the same batch I was involved with, and looks like it too. I also note that the auction doesn't show the glass which raises alarms to me.