It sounds like Amazon gave him a very sizable credit for the damage in order for him to keep the unit, despite the damage. That's where the "cost me money if I return it" statement comes from if I understand correctly.
If he had led his statement about the damage with "this was an open box and wasn't packed very well, and I got a helluva deal" more people would probably have told him to just hang onto it. My 818 sits in a large wooden entertainment center, you couldn't even tell if there was damage because it's behind a door. I'd say keep it and apply those savings towards something else to notch up your system or save it towards the next big AVR improvement in a couple of years.