Pre-owned means it was pre-owned, of course.
Which means the condition will depend on the previous owner.
The maintenance will depend on the previous owner.
Your costs, will depend on how well they kept it.
If they drove it into the ground, you'll have lots of costs. If they maintained it well, you won't.
And since every car is unique to it's owner, and each owner is unique, it's pointless to make a generalization about all preowned Fiestas.