Just an update on my 360 trade-in/ebaying adventure in case anyone cared. Maybe my info well help others who are going to try and sell their 360s to buy an Xbox One.
So I ended up selling my 360 Slim + my RROD 360 (I was honest on the listing that it was completely bricked) + both controllers + 17 games for $200, $240 if you include shipping.
Initially I had listed everything for $250 going on the theory that it's always best to start high, even unrealistically so. When it didn't sell at that starting bid, I dropped it to $199 and it sold.
Basically, my advice to anyone who was in my previous dilemma of whether to trade-in to Amazon/Gamestop/Best Buy or try to sell on the open market is to go the eBay route. I suspect if I had just included the 360 Slim + 17 games I could have gotten $150 for it, which is worlds better than the trade ins I was getting from Amazon.
After all that, and after already putting down $150 on my Day-One pre-order, come release date I'll only be handing over ~$100 bucks. Psychologically that's an easier pill to swallow
Really excited for Xbox One!