Private flats or halls

Why do you require an ensuite?
What city are you talking about?

Unfortunately if you want an ensuite you are likely to have to go into halls of some kind and most are much the same price as University-owned ones - around the 3-4k per year mark to my knowledge. If you can't afford that and cannot get it on finance then you will have to look for rooms in houses.

It’s for my friend who is trans so they really can’t share a bathroom because of their dysphoria. Edge hill halls are like at least £125 for a decent en-suite when they only cost £80 for a decent en-suite at my university (UCLan) which is only 20 miles out

Right. I have no idea how being trans means he/she can't share a bathroom with other people - he's/she's not going to be sharing it whilst using it, you've only got to have somewhere to take a shower, brush your teeth and go for a poo.

Hall prices tend to depend on the build quality, the services/furnishings on offer, the location to the campus/amenities/bars etc, the reputation of the university and the land value.

UCLan is both a better university and has nicer halls so I don’t understand it. It’s a rip off