BC's new empty homes tax and real estate slump has also opened up a lot of rental units. From personal and anecdotal experience, it's much easier now than it was 2 years ago to find and negotiate rent. That being said, you're still looking at $1,700-$2,000/month for a 1-bedroom in the city and roughly $800-$1,000 for a room in a shared space.
Agree with @pzabbythesecond re: costs. UBC has large bursaries that will likely drop your costs down into the 5-figure range. Osgoode’s largest bursary won’t even drop you down into the 5-figure range.
No amount of rent saved by living in North York will make up for the massively higher tuition of Osgoode. Plus you would have to live in North York. No amount of rent savings are worth living in North York.
Osgoode is rarely the right choice for students, in my opinion.