An update: I went and saw the Genius, he did a "test" on my iPad Air in the back room by simply playing music on my iPad Air, he said he didn't hear anything wrong with it (wasn't rattling/producing static at this point) and he said unless he heard it actually static/rattle that he couldn't send it in to get replaced. He also said he couldn't give me a new one since I didn't buy it through them.
Now, the eBayer gave me the option to keep the iPad Air that's under warranty until April of 2015 and he offered me a $110 refund as well, bringing the total cost of the iPad Air to $320. The iPad Air was brand new, everything was plastic wrapped and I also checked over the serials. Being under warranty until April 2015 means if something DOES happen, I could get it replaced for free...hopefully.
This is what he eBayer just wrote to me in regards to the refund: "I'll send you a check or money order, or a cashier's check if you want, but for some reasons of my own - nothing to do with this - I have to get it out to you next week. " Not sure how I feel about receiving the refund outside of eBay? is there a reason he wouldn't want to do it through eBay?
Keep the deal or go for the refund? in a sticky situation.