I disagree. Money is still needed to build all that stuff.
What I meant was the following. This game basically tries to implement a game type (Civ) in an environment (space) where it really doesn't make sense, because it's not humans vs humans but humans vs aliens (the implementation of a background story was the main drive, still some large discrepancies exist). Some concepts that work with humans are not valid when applied to alien species. The concept of money for example might be one of them. The game revolves around the econ system, which incidentaly is quite tricky to get into if you're not familiar with it (because it's a bit fuzzy).
Money is generated by taxes, but they're not really linear, which is odd. You may get money by trading, but what exactly do you trade with aliens? Jeans, cologne, McD?! It's not even the Trade Goods you get eventually... You also get it by surveying some anomalies, another non-sense and partly the motor of your early economy - lame. Money generating improvements, well, those should probably belong to the private sector which we see mentioned here and there.
Money sinks include maintenance costs, which are really weird, since some buildings/ships/bases have them and others don't - that is, it's purely a balance stat, and with the increased costs it can really crash your econ since they have to paid wether the buildings are actually producing or not. Production costs wouldn't really be necessary if there was no econ system, since there's an IU/RU cost to everything, and so an associated build time like in every other game.
Rush buying is indeed a cheesy byproduct. Especially the long-term options in the late game. That there are private sector companies that can deliver in a week anything suited for any race at any point in space is plain ludicrous. Same goes for upgrading in space.
I'm sure I forgot to mention a thing or two. Don't get me wrong, I like to play the game. But all the non-sense and illogical behaviour gets to me at times.
It also seems to me that the econ system, lately, has been sucking the life out of the game.