I purchased my 4308 shortly after its launch for C$2,000. At that time it was routinely listed for >US$2,000 anywhere in the US including Amazon.com. The dealer I bought from went out of business within a year. A few months later I started to think I should have gone with the Onkyo or Integra prepro (I have enough amps) or their top end AVR models only because they have the REON video chip on board. Now I have it figured out, it is a waste of money to have the dollar added REON or any top end video chip such as ABT2010 on board a mid range AVR. So in my opinion if you can get a brand new 4308 with warranty, go for it. The RX-Z7 is even better if you can get it for similar price or even a little more.
I would not recommend the Onkyo 905/906 over the 4308/RX-Z7 based on my perceived reliability concerns.