We use one of these machines and find it to be very reliable and consistent. IMO you would be better off paying the extra to get one of these than paying freight for rejected high moisture loads of grain.
Graintec in Toowoomba are an agent for them.
Anything under that price is usually crap and inconsistent. Always have to be calibrated. Try Farmscan. I have one and its okay, simple to use, many grain choices, but always needs calibrating, especially after rain.
Spending $2500 will get you a good reliable and accurate PFEUFFER HE50, made in Germany I think.