Expected rent can be anywhere from $300 - $500. Generally rent is $300 or $350 for a basement or if the house is far off from the campus. Having stayed in the basement a couple times, I would highly recommend against it as it's damp and laden with bugs. Again, this may not always be the case, but after speaking to a number of people, I've come to this conclusion. There are more expensive basement rooms with rent ranging from $400-$450, which are definitely nicer and cleaner.
Landlord's house or an individual apartment is a personal choice. The cons of having the landlord in the same house is that they can keep reminding you if you're too loud with your music, etc. On the plus side, if there is a problem with, say the shower faucet, you can get hold of the landlord sooner and get it fixed.
If you haven't already come across it, this is a good place to start looking:
https://macoffcampus.mcmaster .ca/classifieds/