Fix old stable or buy small coop?

Im looking to get my first chickens, probably between 4-6.

I’m in a rental house so don’t want to sink too much money in right away.

I have an old stable that’s not used for much, it does not have a concrete floor or door.

Would it probably work out cheaper to make some kinda chicken coop area inside the stable or buy a dedicated one outdoor?

Predators aren’t a big concern besides fox. Nothing else much in my part of Ireland?

Screen off one end of the stable with wire mesh and just add some roosting bars and nesting box and add a raised sand floor?