The pass plus 'should' open up other insurers who can do a cheaper price, although I'm afraid I'm going off friends experiences rather than my own (I'm too old to have had the pass plus available!). My closest friend (unfortunately female so you might be on to something there) saved a small fortune with the pass plus. But other 'new drivers' have also saved more than the lessons cost.
I'm very surprised about the
Ibiza being cheaper though, that's not what I've found. But then again, insurance is definitely a personal thing, and they seem to make up numbers as they go along!