Final answer:
Sam and Bill need $2,000 to prevent the passage of a tax that would cost them $1 million each.
Step-by-step explanation:
Sam and Bill need $2,000 to prevent the passage of a tax. According to the information provided, there are two factory owners who each stand to lose $1 million if the tax passes. So, each owner should be willing to spend up to $1 million to prevent the passage, totaling $2 million.