Okay. So I bought a Nikkor 55mm Micro on eBay and the seller said the lens was clean, free of fungus, no oil on blades, etc. I got the lens and I checked it out. It's got a pretty good amount of dust inside the lens on the various elements. There doesn't appear to be any on the rear element, but there's some on the inside of the front element and definitely a lot on the inner elements. I've never had such severe dust on a used lens. Does this really affect lens clarity, etc? Can anyone give me some advice on this? Can I get it cleaned and does it cost a lot?