Who said the US was paying for any of it? I read that this is part of an international effort, meaning each contributing country puts in a piece of the project. It's Taiwan's lander through and through. It makes perfect sense, putting things in space is expensive and if I were Taiwan, I wouldn't want to pay for the whole project either. But this late in the game you get just as much credit for contributing to a larger project as you would from doing an entire smaller thing all by your lonesome; see India as an example. Were you confused because the cost of the project was in USD? I for one couldn't even tell you what the currency for Taiwan is much less guess at the current exchange rate, that's why it was displayed that way.