I have to agree - that when you view the enlarged photo, you can see the tarnish/rust. But, just because they are tarnished/rusted does not mean they are unusable. I have some that are starting to look like that - I know they are clean and the tarnish comes from everyday usage - and not being properly dried before getting put away. It also depends on what type of metal they are made from. Try a brillo pad to remove surface rusting - because surface rust is just that. It's from moisture and is removable, and does not penetrate the metal. Corners are difficult to clean - and may not have been done carefully by the original owner.
Though I do have to say, that the seller should have stated their condition more carefully in the listing because it is a bit misleading. If someone says they are nice - most people would make the assumption that they are in good, usable, fairly newer condition. When I list things, I always mention even the slightest blemish - so that the buyer is aware of it. I have never had a complaint - always sold my items with no problem, and the buyers actually respond saying that it items were in better condition than they expected.
Try contacting the seller and explain your disappointment in the condition of the cutters (I think you said you did that already) - most sellers, if they are decent people, will work it out with you.