http://www.hutchtech.ca/
Half of our basement is finished but I wanted 2 lines ran from basement to main floor living room and 1 bedroom so they used the cold air ventilation to run the cables (plenum-rated Ethernet).
It was only 220$ for both. Most companies I called were quoting about 150$ per line.
I tipped them well as I called them on a Friday and they came in on Sunday
edit: I was almost tempted to buy MoCa adapters as well but it would cost as much as running ethernet and it would be more devices to manage and point of failure.