The Yamaha rx-v663 is sold for 500US$ on Amazon it much over my budget, do you have any concerns over the marantz 4002?
They are not the only place to buy it online; here is Yamaha's list of authorized online dealers, as well as the place to go to find local authorized dealers:
http://www.yamaha.com/yec/customer/dealer.aspx?CTID=5010030
I have no idea which would give you the lowest price, or whether or not there are significant differences in price from them.
With the particular models you mention in your opening post, at the prices you mention later on, I would probably go with the Pioneer. But before doing that, I would check out all of the Yamaha authorized online dealers, as well as any local authorized dealers there might be, to see if I could get a deal on the Yamaha RX-V663.
The reason being, the models you mention do not support the new audio formats on Blu-Ray, so there is a good chance you will want to replace it in the not too distant future. Whereas the RX-V663 is about as "future proof" as anything at the moment. You might also look to see if you can get Pioneer's lowest unit that has the new audio formats; I believe it is the VSX-1018AH-K. Or, you could wait for the new models coming out soon, when there will probably be these new formats on lower models. See, for example:
http://ces.cnet.com/8301-19167_1-10137163-100.html
Of course, it is not available yet, and I don't know if it will have all of the features you need, but it might be worth waiting until April.