The KS10 has been pulled from US Costco stores. Conjecture is that they were pulled because of power management issues. Who knows if they return or are eventually replaced by a KS11 model.
One poster also reported buying the Philips HearLink and getting $200 back when they were fitted with the new aids. That helps make them more affordable, but still not the $1399 that Costco was charging for the KS10.
The lengthy earlier thread: