Three points. First, I think Peter M. has it right: I assume you are an amateur and not a pro, therefore the amount of satisfaction you are going to get from your $280 is really the thing to think about. Some folks cannot enjoy an inexpensive purchase if they feel they got screwed on the deal and if you will not be able to get your $280 of enjoyment from this piece of gear, in my opinion you are better off returning it, even if you wind up spending more money on a different lens. If you are not a pro, then this is essentially an entertainment expense. If you can be honest with yourself about whether this is an issue for you, then you can reach the right result in terms of your return/no return question.
If it were me and I received gear that had not been accurately described I would either return it, or try and figure out how much the "difference" was worth to me. In your case, let's say that the most I would pay for a lens in the condition you described is $100. I'd then try to negotiate a refund for the difference between that amount and the amount I paid. The money would probably go into fixing the problem -- see below. If the vendor would not agree, then back it would go and they could try to find another buyer who would pay that price.
If you test it and are pleased with the results then you may decide to keep it and use it as is. If the scratch is very thin, probably you'd perceive this on film as a hit to contrast and a tendency to flare more.
I recently bought a rigid Summicron for $115 from a store here in Burlington. I could tell that the lens needed a CLA ($125 from Sherry Krauter), but that the mechanics were sound. For me, that's still a good deal on a classic lens.
Finally, you can also look into having the lens polished and recoated by John Van Stelton (
http://www.focalpointlens.com). At $250 or so for the process (without any refund from Adorama), you would probably then have spent more than the average cost of one of these lenses, but you'd have the benefit of modern coatings on the front element. Focal point has a little write-up on their website regarding whether it is technically advisable or not to fix this sort of damage.
For used gear, I try to stay away from the NY stores. Despite their excellent reputations on new stuff and customer service, even B&H and Adorama fall short on used gear compared to other vendors (e.g. KEH) in my experience. My own theory about this is that they get a lot of gear from the NY professional and art-school crowd and it has been reeeealy used hard. They also tend to have an inflated idea of what a banged-to-cr@p lens is worth, in my limited experience, because they are looking at one another and the rest of the NY market as a reference point, rather than the national market (which would be more reasonable in these days of the world-shrinking internet).
Good luck with your choice.
Ben Marks
