I haven't broken a spoke in fifteen years of riding potholey streets on skinny tires with my 185lb body.

You will need to learn hand signals, tire repair and, if you ever ride in the rain or snow, chain cleaning.

Since you'll also be fitting lights, tools and a bag at the very least into your budget, you're stuck with used off of kijiji or craigslist. Last time I was in Toronto, the roads were glassy smooth compared to here in CNY, so a road bike sized 55-59cm should do you fine. If you're patient and willing to surf the web and drive a ways out of town, you can easily find a very fine barely-if-ever used steel Trek or Specialized or japanese road/touring bike for under $200.