I was also looking to get the hc3 and found those same sites offereing the camera practically at half price.
From previous experiences, places like this are very high pressure to buy extras and extended warranties etc... Usually some of the extras are things that you would want, such as, extra batteries, filters, etc., while others are not needed or very low quality. (Extra tapes, tripods, soft cases)
If you're about to buy from such a place, I'd recommend this:
1) Use a credit card that will back you up and not leave you alone ot fight the retailer. AMEX and MBNA MC have been excellent for me.
2) Ask about manufacturers warranites, return policies and re-stocking fees and be clear on what they cover and how they apply.
I don't have 1st hand expereince with this particular vendor, and it seems to be the same vendor with two sites, but I have had pretty good luck buying electronics from places such as these. Specially when they have as many good reviews as these two sites. YMMV
Also, they may tell you that you need to add extras to get "that price". I don't know how true this is, but worst case scenario even adding their cheapest extra package the price still very attractive.
Good luck!
Wys