I used to work at a holden dealer, the sort of jackaroo you get for that kind of money would be as good as any pajero.
the motors running gear are all isuzu so its good quality gear (if looked after) IMO.
Some people say that the suspension is a little soft/ lopping around, i would tend to agree a little but a good set of shocks should fix most of it up.
the older square type Jackaroos tended to be rust buckets and no were near as good as the rounded/newer type ones.
IMO you can get a lemon in any car so you need to be careful and take your time when buying a car especially a 4X4.
hope this helps
neil