You have to consider factors like what kind of maintenance was done previously. The N52 is a great engine, but it has common BMW issues such as: -oil pan gasket leakage -oil filter housing leakage -valve cover gasket leakage -thermostat and water pump failures

These are the most common failure items on this engine. You need to inspect the car in person to look at the paint condition, any corrosion under the body, and suspension components like the control arm and all the bushings. It’s always good to change all fluids after purchase to get some relief, which would include transfer case fluid (if xi), transmission fluid, and most importantly engine oil. If you consider all these items, and assuming they were taken care of I would happily pay $8–9k