Beyond rent, consider:

As noted by others, taxes are higher in Quebec, e.g., the lowest tax rate in Ontario is 5%, and for the same rate in Quebec it is 15%. It only gets worse from there.

Another reality of Quebec is you really will want a car, and that traffic will often be awful. Gasoline adds up.

Healthcare is a nightmare on the Quebec side; you will NOT find a doctor, and it won’t be easy to find a clinic either (unless things have really changed in the past few years). If you seek medical help outside of Quebec you will have to pay cash or card on the spot; Quebec will reimburse you for what THEY pay for the same service… it is ALWAYS less than you paid (years ago Quebec would pay $38 for a $52 Ontario doctor charge). Now… think what a hospital visit will cost you. Moreover, doctors in Ontario often will not accept any Quebec patients at all. Any major medical work is a trip to Montreal or it’s environs in many cases.

Don’t do it.