JK, it best you just figure up the best estimate ya can. As said in another comment you won't be getting the information anytime soon. The Streetcar doesn't exactly follow Sarbanes-Oxley Demands and standards.

As for the number, with the price of the Streetcars and operations, they would be much higher than busses but not too much. Being that busses have lower, much lower ridership in general, and that busses have a negative air of existence about them one often related with squalor, the cost difference isn't really much of a concern.

The problem I harbor with the Streetcar, is A quality for the money, and B price of the vehicles. There are better options, there can be better options than what has been implemented. The other issue is, including operations Streetcars SHOULD be cheaper, including all infrastructure used directly associated to the mode, it COULD be cheaper...

But I digress. Some idealogical issues I want to address with certain postings.

"care of all taxpayers in Portland equally whether"

When taxes are collected, by supposed vote of the people, you've given up your opportunity for choices at that point. You don't get what "you" as an individual want but only what the majority want. The individual is the smallest functional minority and cannot be compensed for or considered by the functions of Government being it is concerned with "society".

All a minomer of original founding intentions, but it is the world which we live in today.

"People outside of downtown pay the majority of taxes."

Only because for the last 30-50 years Cities and the Fed Government have encouraged and pushed people from downtown by subsidizing suburban growth post Streetcar. Now the cities can't afford the streets so smart cities are coming up with alternatives that don't leave the budget empty. Take similar size cities as Portland that has a more "road building" and "road subsidizing" mentality and you find utter chaos and hours of sitting traffic a day WITHOUT another option to get around.

Portland has the traffic problem, that's a symptom of our road funding mechanisms and their inability to control and meet demand per market pricing. But in Portland we do have other choices about how to live, get around, and a far better quality of life. I don't always agree with the funding priorities and the way it is done but the fact is it's the only way to rebalance various lifestyles after 50 years of Social Engineering and City Planners pushing suburban growth styles.

You'll find in the next 10-20 years the "taxpayers", the ones having lost real individualized choices, will be the people living downtown. Just wait for the abatements to run out. Then of course, with those massive costs directly impacting the people that will be living there, there could be a mass exodus of downtown when it begins to occur.