To echo Major's sentiment, so long as you're buying from a reputable dealer, refurbs are a great option. In fact, about 60-70% of my two HT setups consists of either refurbished or used items. In my main HT setup, I saved several thousand dollars buying used and refurbished that allowed me to buy the equipment I otherwise wouldn't have been able to if I went the new route.
Another frequently used refurbished site is uBid. In fact, they've recently had the Onkyo receiver you referred to for sale and it comes with a full 1 year warranty direct from Onkyo, so this is as good as you're going to do new. If you felt like throwing in the extended warranty from uBid, you can do this as well. They currently have the model down from the one you mentioned
here. I believe the HDMI may be the only difference between the 703 and 803, but if you're set on the 803, I'd keep a lookout for it there unless AC4L has a better deal on it.... -TD