When someone was dusting a piece of furniture off near this, they laid their Endust/wood oil drenched towel on the top of the box for an hour or so and it produced that surface stain you can see in the pictures. It isn't any excessive dampness or more invasive or corrosive thing.

As with other very large things I have sold here, the shipping is wholly your responsibility.  This box is not palletized. When it was delivered, two fellows (big fellows) simply lifted it out of the truck and walked it into my house despite it being 320 lbs. 

The least expensive way for someone to buy this shipping cost wise would be someone in my zip code (45449 Dayton, OH) with a pick up truck and strong people to put it in and take it out. Otherwise, have some trucking/shipping savvy friend set your pick up. We'll be available any time during business hours Mon- Fri, 8AM-6PM EST to give access. eBay's automated system doesn't allow me to select pick up only so I've thrown in an approximate flat rate freight of $300 which, from my little research is likely somewhere near the higher rate you'd find. I'm not making any representations here just trying to make it fit eBay automation. 

I cannot offer a return. I doubt any warranty is transferable, although all that material will still be in box, unprocessed.  Consumer Reports gave this a very good review. If you have questions, please feel free to ask within the eBay system, please.