I'm not completely sure on this situation, but I believe a HD-ready TV doesn't come with a HDTV tuner (meaning you have to buy a separate box to watch HDTV channels). If it's a HDTV,you can just plug in the TV and watch HDTV channels without a separate box.
As far as your Xbox (or any other HD enabled device like a PS2 or DVD player), you can use it on a HD ready TV without a separate box (just get the component cables).
If anyone who understands the topic better things anything I've said is wrong, please feel free to correct me.

EDIT: Also, can you give us a link to these TV's you found? I'm pretty sure you won't find any HDTV for less than $400 (that's the lowest price I've seen, it was on Bestbuy.com)
This post has been edited by Trevante: Dec 29 2004, 09:41 AM