Where exactly can I see the spending breakdown of a planet? What does it mean, and what drives up spending?

On a new game, I see planet Dratha has a 'spending' of 7BC. Acceptably low, I assume it's research money.

I start building a factory and it goes up to 12BC - 5 manufacturing points?

I colonize Dratha IV - and right away there's 14BC spent on Spending on top of 12BC on maintenance. Nothing is being built - so why the hell am I paying so much on spending? It has nothing built on it, there is no industry, and only the two default research points.