I respect Peter's opinion, but I do also think that the issue is not so black and white. The question here is not one of good/bad, right/wrong, etc., as it is being made to sound. I have bought a summicron 50/2 from a reputable dealer off eBay, who said the glass was perfect...except he didn't see those little spots of brown...in several elements. I paid a good deal for the piece, IMO, relative to the amount it will cost to get the lens cleared, if possible.
The question is what to do. I am of the opinion that after CLA the camera will be everything it is hoped to be, if not as gorgeous. We should all aspire to this....
I think a contact to the seller is a good idea, but the legal/structural way of handling through eBay always winds up with mud on both individuals, and solves nothing, often.
For sale: 2002 Ferrari Testarossa, 30,000 miles, needs a wax job. 5,000 USD, or best offer. What does the car look like in YOUR mind? Yes, the price does, relatively, matter a great deal. Right is right, and wrong, wrong. BUt what should you do? You have the camera you have wanted. Get a little cash back to pay for CLA if you can, unless you paid less than it would cost. If you did this, fix it, and laugh to yourself for a long time.