Think of the projector as your computer monitor.  It only knows what you put into it.  You need a cable box/direct tv/vcr/etc.....
450 bucks will get you half a screen for the projector to shine on.  You won\'t find a cheap worthwhile LCD for less than 3500 right now.  But I wouldn\'t get an LCD cause they have an awful time reproducing black.  It comes out grey.  I would only get a CRT or DLP.  I have a CRT projector.  You can find them used on the internet for about 6 grand.  New they are over 30,000..  
DOn\'t forget though that tv is about 500 scan lines, you blow that up to 100+ inches and you start seeing scan lines.  I never bothered getting a line doubler because I have an HD receiver which makes all signals 1080i so I don\'t see scan lines, but I do see scan lines with my PS2.  It doesn\'t look bad, but I wish I had a doubler for it.
Anyway, my point is, unless you have at least 5000 in your pocket, don\'t bother...