Not sure where you are getting this, it could be that you are not taking the caliper carrier price into consideration. Per the ECS tuning site, I am seeing $255 for each caliper plus $178 for each carrier so that is $866 for calipers and that does not include rotors, splash shields and pads which is going to be another $300.
https://www.ecstuning.com/Volkswagen-Golf_VII--2.0T_Gen3/Braking/Caliper/
I did my fronts on a budget and was able to do it for $606. I purchased a set of used PP calipers with carriers for $310, $170 for Zimmerman rotors, $60 for pads, and $65 for shields. So you may be able to approach that price if you buy a used set of rotors and catch a deal, but from ECS, new, no.