Seattle Transit Blog has a good summation of a summation article in the PI about Cost to expand light rail under debate.

Now my summation: The No campaign is using a questionable way to count the amount of taxes collected for Proposition 1 in order to scare people into thinking that Proposition 1 is TOO expensive.

Rather then go into detail on why, I'll leave you to find the information on the blog posting here

It boils down to... if you are interested in seeing some REAL long term strategy for dealing with traffic in this area then Proposition 1 is the way to make that happen.