No, it is not a good decision to buy an 28 year old Pajero
No, it cannot run as a Motorway vehicle unless exceptionally maintained and driven below 100 km/h
Get it properly inspected from an SUV specialist workshop that understands Intercoolers, Turbos in addition to SUVs
Between 18-25 depending upon condition, online prices on Pakwheels and Olx are overstated