Bear in mind that in most previous civs (though not Alpha Centauri), being able to rush buy production with gold didn't become available until much later in the game. You either needed advanced governments or advanced civics (which were unlocked fairly late in the tech tree) before you could do so.
I didn't take care about this, but do we earn money as for wonder if we rush buy a building in production ?
Civ II : I remember being able to cash rush from turn 1.
Yes, Civ V eliminated the discount for partially constructed buildings / units that had been there from the beginning. (That decision was made during development; as a consequence they turned off the AI cash buying of buildings to keep AI from wasting cash). However I do note that prior to Civ V, you still had to wait for your next turn for the building / unit. In Civ V, you can cash rush multiple buildings in the same city the same turn.
I like the way it is now in Civ V. It´s more fair to play against AI.