For standard cars, in effect no cars over 750,000 Cr can be traded I believe. And there won't be any cars costing between 750k and 960k due to mileage limits on the race / tuner / concept cars.
There are no cars with a 'new' price between 750,000 and 1,000,000, and the 1mil cars can't be traded whatever their mileage. (There are a couple premium cars that fall in that range though; WRC and JGTC If I recall.)