My head hurts.

Not really. If money is mismanaged, costs can inflate. Man hours would be a better indicator. 

In software development, they are directly linked.

Not necessarily. Not saying it has no link, but unless the link is certain, it can only be an assumption.

To me, the effort is partly the money, but also the fact that they started the game build again when they weren't satisfied. 

Yes, a very good chance. I have several friends who got GTA 4 first, but plan on absolutely buying Mario Kart.  That's not to say that it will crush GTA 4 anytime soon, but I think that by the end of the generation Mario Kart will absolutely have more sales than either the Xbox 360 or the PS3 version of GTA 4, and possibly more than the combination.

I have both games. Frankly, Mario Kart is a much better game. GTA 4 is fun, though, but pretty soon it will be done and on the shelf while Mario Kart is going to be played for a very long time to come. The online multiplayer is a blast also.

Congratz on being one of the few people that would actually compare waist there time in comparing these two games, i mean come on a sand box gangsta shooter thing whatever you want to call it against a "kids" car game.

YOU HAVE REALLY OUTDONE YOURSELF

 There are threekey things in a game development project and changing one of those things directly affects the other two: manpower, time (and money), and quality.

If you want to raise the quality of your game, it raises the time requirements (and cost) and the manpower (hours).  If you want to decrease your man power you will gain more money (or lose time) but lose quality.   If you want to increase quality, you increase manpower and you increase costs and time spent.

Also, according to the mythical man month doubling your team size won't half the amount of time it takes to finish a project.  Think of it as it takes 1 woman 9 months to deliver a baby, it doesn't take take two woman 4 1/2 months to deliver one baby.  Adding more people to a project should decrease the time but there are still a lot of dependencies that require one thing to be finished before something else can be done and adding more people doesn't change that.  Don't think that applies to the conversation but whatever, it popped in my head.  

Sort of like how you can't double the temperature to cook something twice as fast.

Anyway, do you think Nintendo just slapped MK Wii together? 

In this thread and the "Wii Fit: Hit or Miss?" thread, hanafuda's avatar is eerily appropriate. Maybe the joke's on the rest of us?