Wait - You want to watch a DVD, or you want to watch content which has been uploaded onto a server somewhere and is only available via a PC?
A DVD is a DVD, not a stream from the cloud, so it would be really helpful if you could detail specifically what you want. If quality matters, then the cheapest solution won't deliver. With most current cameras shooting in high definition, then I would expect a requirement to play back with that level of quality, which can't be delivered for the lowest cost option.
The lowest cost option is not going to involve HD or HDMI or digital... It will be, as mentioned, to modulate the video feed onto a specific channel and then tune your TV to that channel to watch it. You may need to inject the video into a coaxial line which may be in place already, and frankly it is not something I have specifically done so I won't be able to say how you would specifically accomplish this.
HUDL doesn't seem to offer any stand alone playback hardware and is only viewable through a computer/tablet device, so you don't have any real options if you want output other than splitting the signal out of a PC using the previously mentioned HDMI splitters and extenders or by putting a cheap PC at every TV location.
Monoprice does have a 1x8 HDMI splitter which includes cat5/6 cable receivers in the box for $270...
This would probably deliver the highest quality for the money IF it works properly. I haven't used it. I was about to recommend this:
with 6 of these...
Which would have run about $1,200, plus you would still need a bunch of HDMI cables.
Regardless of the cat-5/6 solution, you will need dedicated cat-5/6 run from the splitting device to each display.