I bought a lens from a long-standing member of this forum, the transaction and communication were great, however the lens, not so much. When the lens arrived I mounted it and took some test shots. It worked perfectly fine wide open but with smaller apertures I was getting completely blown out photos. I took a look at it while using the DoF preview button and noticed that the aperture was barely shutting even set at f/22. When I did get it to close I noticed oil on the blades so I then contacted the seller who claimed he had just used it on a trip and had no problems with it.
The seller offered a refund with no trouble but he is asking that I return the lens prior to him issuing the refund.
Now despite the fact that he has been a member of this forum for three years and has many positive feedbacks (and only one negative that I could find due to this forums lack of a negative feedback section possibly) I am still wary of sending the item back to the seller without some sort of guarantee that I will get my money back. If I had some course of action if I were to ship it back and not get my money I would have no problem doing so but I am unprotected at this point.
The seller says that he has been involved in a transaction where he refunded money and never received the item, to which I said he should have been protected by paypal just as if he were buying an item from someone (after all isn't that what you are essentially doing; buying your item back?)
Now, at this point, I am not here to give the seller a bad reputation, I am simply starting this thread to see what others would do/have done in this situation.
Am I silly to want the refund before I send the item back? I certainly wouldn't expect someone to send me an item I am purchasing before I paid for it.
Should I file a dispute with paypal? I would really hate to do this as he seems like a good guy, but things are not always as they seem on the internet. I just do not want to send the lens back and never see my money again.

