cost的一个用法？

The main issue today is that the bandwidth necessary to broadcast and store uncompressed digital signals is cost prohibitive。可以帮我解释一下这句话吗,谢谢！

今天主要的问题就是对于broacast 和store uncompressed digital signals 来说是必需的broadcast贵的让人用不起.  

The main issue today is that the GMAT test neccessary to go to study in US and get fee loan is cost prohibitive.