Hmm, that Instant Sale thing on eBay is pretty interesting, I hadn't heard of it until reading this thread.
They are offering $332 for my 16GB Wifi+3G and $362 for my wife's 32GB Wifi.
Do they charge you any eBay fees like when you sell it through normal auction?
I currently have mine on eBay, it has 39 hours left and it's at $224 with 19 watchers so I'm hopeful it will go substantially higher than $332. I do have to pay shipping out of that (offered free shipping) and eBay will take a big chunk.
I do have an Apple Dock and XGear case with it as well though.