There are many good places to live in Ontario. Toronto is probably out, given your house price range. One possibility would be London. It is centrally located, two hours from Toronto, one hour from US border.
I have lived in London for one year (my son is doing his medical school there, he will be done in June), London is a very nice city, not too big.
If you want something smaller, try something like Woodstock or Strathroy, both on major highways and not far from London. Or there are places like Guelph, Kitchener etc. (I assume you want to stay close to major highways). There you are going nearer Toronto, but away from US border.
I have been told that Sarnia is also a very good place to live (Windsor not so good, there is high unemployment). But then you are moving away from Toronto (three hours), though it is right on US border.