Bath Braitol travel pass is it worth it?

Hi there, I am a student who is going to the UK next year. I've just got an offer from both Bath and Bristol and am still deciding where to go. From what I have gathered, as I don't currently live in the UK, Bath is probably better to live in since it's safer and more convenient due to it being relatively small. As for Bristol, though cheaper, is a bigger city which I'm not used to and there is heavy drug usage (again, this is just what I've heard) which throws me off. However it's probably more fun as there is more stuff to do and I do like a good nightlife. Therefore, I'd like to go to Bath and just catch the train to Bristol when I need to but how expensive is it?? I'm looking for some travel pass I could purchase but I think that would be £200 per month. It seems pricey but maybe somehow it's worth it? Are there any alternatives? Or should I just live in Bristol instead?