That Pajero seems to be very nice in pics, the owner has had it for 15 years you say, the jeep is 24 years old, so I guess it was somewhere else for the first 9 years, check the documents carefully, have a CPLC check, get a mechanic to check the engine and the body for you,
Also check where the vehicle was auctioned from, ask for the auction sheet to suggest that the vehicle has been auctioned etc and ensure it corresponds to the reg, chassis no. etc,
Also ask to see the original number plates and documents, verify that it has been with the same owner for the last 15 years and the body is not replaced, the body is very clean for Karachi, I can't see any rust etc on it either which is great, people often buy auctioned vehicles in poor condition and replace the body, your mechanic will also be able to suggest whether the body has been replaced or not. Also let us know which engine it has, is it a 4D55 or 4D56, that isnt a condition, it's just curiosity so don't freak out over it.
There is nothing wrong if the body is changed etc as it's legal to do so, it does however effect the value, you would also need to consider that the auction registered vehcile is slightly harder to sell and also goes a bit cheaper,
Also verify the mileage, it's surprising that the vehicle has travelled on average 7,900km per year over the last 24 years, again, I'm not saying its impossible, just surprising,
If the response to all the considerations mentioned here are affirmative then go ahead and make an offer, as Machine said 500 - 550 is a decent price for a vehicle in this exceptional condition, I would second that but would lean closer to 500.