No offence but I would avoid the 2003 model year and pay extra for the 2006. 2.3 Million is an ok deal but given the year and the fact that its 15 years old, i would avoid unless you got deep pockets for maintenance. Even then I would say increase your budget to get the 2006 or the LCI model.
A BMW 7 series for the price of a brand new GLI seems so tempting but remember the parts are going to be BMW expensive and I am not sure how well maintained the 2003 is and whether its a ticking time bomb with differed maintenance.
Buy the latest or the one in the best condition based on your budget. But personally if i had 23lacs i wouldnt be looking at an old E65 7 series, maybe a E38 series. Look for them in the 3-3.5 million range where you get excellent examples with good maintenance history from Dewan etc.
Always try to put one on a lift and check all suspension work and make sure all electronic items work inside the car. Engines are stout and but transmission modules do tend to fail so check if its shifting through all gears properly. Air conditioning too as its quite expensive sorting it out on it.