The amazing this is the power supply modules - 3 on each board. These are high-end DC-DC converters which cost $50 each in wholesale quantities. With 15 viper boards per miner, that's $2250 for the DC-DC converters alone!
FWIW you can find them for as low as $35-$45 online in bulk. Not to mention Chinese knockoffs cost far less. Not sure what converters KNC uses, but their in-house-cost for Jupiters was ~$1k. Excellent analysis though.
Overengineering is better than underengineering--it seems like in the crypto world it's one or the other.