How many miles for a Toyota Camry would be considered too much?

It depends on if you are buying or trying to decide if you need another car. If you are planning on buying higher than 140K is too much especially if the previous owner did not take care of the car.

If you are thinking to replace your car, then it depends if you took proper care of the car. Toyota Camry can go up 200k without any problems. Also if price of a single repair is same or higher than the price of the car you might want to get rid of it.