He is talking about a new IS350 but you get the idea
These car engines are basically built to last a really long time so 150K is pretty decent
I would take car over to lexus and get an assessment on the car.
Also the pricing might be another issue
Looks like car has been maintained ok, from the pic you provided though
also get a carfax ,
look around also and be patient ..
Goodluck and welcome to CL