I'd rather buy from a Canadian supplier, and there are a couple that I know of in Vancouver so I may as well keep it close. I am pretty sure on this Nine Continental kit w/cycle analyst, $450 CAD. Seems pretty solid of a kit to me. Plus 48 A123 cells (Tech Ex eBay supplier) for $290 shipped for ~340Wh for up to ~20 miles range at 40km/h?
http://www.ebikes.ca/store/photos/NC26R_Fast.jpg
$750 for total system cost, plus a little custom work I might do to make a nice sealed aluminum battery box.
Do the calcs I made look right to you?