How many km should I be able to get out of a 2007 Kia rondo (4 cylinder) and is $4000 a worthwhile price for one that’s already got 130-thousand km on it?
Well the vehicle is 11 years old so there is no way to say how long it will last. You use Kilometers so that means you are not in the US as most of us are. As for value find a vehicle pricing site ( Kelly Blue Book type sites ) and see what the average value is for your area. Also pay a fee to have it inspected by a mechanic and that will increase your chance of not buying a disaster waiting to happen.
Your question is akin to asking how long a 13 year old yard sale refrigerator will last. No one on Earth knows.
Agreed an inspection is a must. Also factor in a new timing belt job. If the seller says it has been done but can’t back it up with receipts then you should consider it lying. The last thing you want is for a T-belt to break on an interference fit engine.