Case 1: People loss their their job and cannot afford to pay for the martage.
Case 2: People find a job somewhere else and they need to move to the new city.
If you want to find a low price house, you can try to look for the one with the following wording - power sale (bank took over houses) , sold as is (you need to fix the house because lack of maintenance)
60-70 thousand house will be an old house and you need to invest some money to fix it.
website for housing -
www.mls.ca