Wow, real nice names! I think hugegrowth hit it on the nose about the traffic. I read somewhere that jobs.ca gets like 1500 - 2000 uniques a day, so I guess that explains the $600,000.
career.ca and careers.ca are great names, but I don't think they get anything like that kind of traffic, I'm thinking maybe 50 uniques a day. So my "guess", without knowing the traffic, would be about $12,500 to $17,500 each.
Good luck if you decide to sell them.