if you're worried about a few hundred here and there on ball-joints, and other bits and pieces, don't buy an LS400 - the parts are a kings ransome, the labour is usually £50/hour non-franchise garage and up to twice that at official lexus places. they were a richman's motor when they came out, and they still are, just a bit lower down the pecking order.
having said that, i lavish TLC on mine, way beyond what is sensible, and enjoy the look, feel and presence of it - but i still run an escort to take to the shops, dogwalk, council tip, etc. and with parts and labour that are a pleasure to pay for, at about a quarter of the cost of the lexus.
just go in with your eyes open AND WHATEVER YOU DO, DON'T OPEN THE BONNET OR YOU'LL LOSE YOUR HEART FOREVER!!