Don't know if anyone has already seen this website http://www.ewayco.com/51-embedded-systems-100-PC-mini-ITX-low-cost/12-mx-800mhz-low-cost-pc-embedded-system.html
but they have very cheap mini pc's.
I think the "MX-SA Socket System for Dual Quad Core AMD, NVidia, 1080i, 1080P, HDCP, HDMI, H.264 BluRay, MPEG2 $190 qty 1" would make a perfect MD. Just have to add CPU and Ram.
Here are the specs:
MX-SA Socket System: AMD AM2+ Dual Core CPU, NVidia GeForce,
NF-8200GFX, 1080i, 1080P, H.264, AVC video acceleration
Dual Display, HDCP, HDMI, BluRay, MPEG2, VC1, ,Direct X 10,
HT 2Ghz, DDR2 800 Ram, 4 SATA2, RAID, DVI, 2Gb Lan,
8Ch Audio, 10 USB (some hdr), VGA, PCI slot, CE, FCC, RoHS
Oh the price is in US dollars too.
Depends on your currency conversion rate whether this suit.