I think you should get a special bog-roll locker in the bathroom, where you can safely store your precious fluffy bum-friendly bottom tissue, away from the greedy bottoms of your flatmates.

In terms of the stuff ishkhara and I buy, it's usually of the slightly soft but slightly harsh Lidl variety. It's nice to have multiple-ply bum couture (the cat makes good for bottom relief... Which sounds bad and wrong) but it's not considered a necessity by us.