I researched what I wanted and watched 52" Samsung LCD TV prices like a hawk for about 9 months. I ended up getting a used 52A630 back in May of 2009 through Amazon Warehouse Deals. While it was a bit of a headache at times to go through Warehouse Deals, it all ended up okay as I got a great TV that has been working flawlessly so far.
I saved a good $300-$400 by going through Warehouse Deals. But I had ordered a 52A650 from them in April 2009 that I rejected upon delivery due to a problem with the screen. I risked going with them again and after a bit of a struggle with delivery I ended up with a great find in this 52A630.
The people at Warehouse Deals were at the very least helpful and willing to do as much as they could do to help.
As for the TV--couldn't be happier with its performance! The picture looks amazing with our HD cable. I'm looking forward to my next purchase of a Blu Ray player to use with this!