5-6k tops depending on condition, IMO
Not too many for sale so its hard to judge. Quick scan of trader.ca and all of ebay motors only turns up maybe 6 results.
Scroll through ducati.ms forum classifieds for bikes... there's maybe 1 749 for sale per page, mostly newer than 2003 models ranging from 5500 to 8500 for the S. Personally I'd just set my sights higher on the 999, unless you really can't afford the insurance.
Or go to the states and get this 749S, you probably won't find a better deal in Canada. I wouldn't even bother with a non-S model, these are just way cooler.
http://www.ducati.ms/forums/128-bikes/337225-fs-2005-749s-2.html
(dont let anyone tell you that you can't ride a Ducati 4000km back home

lol)