They are great cars but thirsty for gas and very expensive to repair. It has low mileage (if the mileage is legitimate), but if the maintenance has not been up to date, you are looking at very expensive bills. 

Definitely have a mechanic check it out. I loved mine, but repair bills get very expensive, very quickly. You want to make sure maintenance items have been completed. 

I am not sure an LS460 is a good vehicle to own for a student just from a total cost of ownership standpoint (maintenance, repairs, fuel, insurance).  I would get something more economical like a Toyota Camry or Honda Accord.  If you wanted some luxury, maybe consider a Toyota Avalon.  Repairs on LS460 or even something like replacing a knock sensor or starter on those can easily cost several thousand dollars when they go (~$3,000 if you take to a shop since intake manifold has to be taken off and very little room to work back there).

If you do get it, you could offset some cost of ownership by joining a ride service like Uber or Lyft and chauffer people around.  I think you get more fare if you drive a luxury car over a standard automobile.  It would also be the roomiest car compared to what most your friends have. Be sure they cough up gas money if you take them with you on spring break.