probably its not possible to build a fully functional HD media director for less that $300-$400. However you could use a Digital Media Adapter to access the content on the core (The UI will be clunky and you WON'T get any integration or home automation functions). Possibly the cheapes way would be to get a Popcorn hour http://www.popcornhour.com/onlinestore/
($179 I think) and load Swisscenter http://www.swisscenter.co.uk/
on the core to give it access to the content. The TV access will be really clunky but possible. This will give good H.264 playback and be silent.