编辑以下句子，使它更加清晰和易读：“虽然公司每月有1,000台机器在运行，但是只有50％的机器需要进行维护，而且这些机器的维护费用很高。”


虽然公司每月有1,000台机器在运行，并非所有的机器都需要维护。维护50％的机器会导致很高的维护费用。
The sentence can be edited for clarity and readability as follows: "Though the company operates 1,000 machines each month, only 50% of them require maintenance, and the cost of maintaining these machines is significant." 

Revised: The company operates 1,000 machines monthly, but not all require maintenance. Maintaining 50% of the machines incurs a high cost.