I'd look at the cost of living in Edinburgh, Glasgow, and Dublin. Consider how much you'll need to spend on groceries, housing, eating out, travel, ect.
Even if you'll be living in student accommodation at first, will you later move out? If so, you'll want to look at rent prices in the areas.
Also, consider the entertainment and dining scene - are there lots of budget friendly options nearby?
Another thing to consider is proximity to services that you'll need to use, and any costs associated with this.
Whilst the decision should be about the uni itself, these components should definitely be factored into your choice.
I hope this helps, and if you have any more questions feel free to ask me. 😊