well, think about that graph in a different way, let's just assume that salaries have stayed the same in the last 20 years of game development (I'm sure they've actually gone up ALOT). So you're looking at maybe 50,000 per year per employee on average. A snes/genesis game could be made in 9 months with 10-15 people on staff so you're talking maybe a half million per game and those were likely the more expensive titles as there were also many games made with smaller staffs in even less time. But whatever, let's just run with that 500,000$ figure for a 16 bit title. Move on to the 32 bit era (I'll say 3d0 up to nintendo 64) and suddenly you need to hire twice as many programmers/artists/testers and such and the games need 15 months to finish instead of 9 months. So now we're talking 20- 30 people working for 15 months on something. Again using that 50,000 per employee ballpark we get roughly 1.5 million dollars per game .. again there were certainly games that were made for less but there were also games built in 9 months that had more then 30 people on staff. So we're talking a 3 fold increase going from 16 bit to 32 bit.
Now we move onto what I'll dub the ps2 generation (dreamcast, ps2, gamecube, xbox). The 3d got more complex, textures more detailed, programming harder. Now we're looking at 18-24 months to build a game and staffs in the range of 50 people. Still maintaining that 50K per year salary we come up with 4-5 million per game , again some games came out faster then that but likely had larger staffs. Basically we're looking at around a 3 fold increase in costs once again.
I almost don't even need to do the math on what a game costs right now, most studios these days seem to have near 100 people building games that now take atleast 24 months to finish with the odd big release title having closer to a 30-36 month development cycle. 3 fold increase this time would put the minimum cost of a 360/ps3 title at near 15 million.
The scary prospect to consider is that building a game on the next generation of consoles, given this fairly constant increase is going to be a movie budget level commitment. We're talking 40+ million for a game to actually use the hardware, staffs of 150-200 people working 3 years minimum to get something out the door. Something is going to give and my guess is it'll be the length of games, you'll wind up having companies investing 15-20 million to make "episode 1/2" of a game and further entries will come out every 6 months for a cost of 50% the original disc. Studios will need 5 year plans to figure out how to turn a profit on their games and I suspect many studios will go under as a failed launch will be the end.
On the other hand, the next gen consoles may well go the wii route , offering a cheaper better designed console with minimal graphical increases to keep development costs lower.
For the record, using the same formula to figure out the cost of final fantasy 13 produces a rather daunting number. I mean we can figure by the time it comes out to ps3 in japan that it'll have had a 4.5 year development cycle (54 months) multiplied by a minimum of 150 staff(counting the cg movies /actors and such). This means development of ff13 alone cost north of 30 million dollars (like absolute bare minimum). Factor in other costs of a game release such as advertising , disc production and foreign language development, the 360 port. I wouldn't be surprised if FF13 is nearly a 100 million dollar investment when it's all said and done world wide. Now in japan /asia there'll be a square enix tax on the game , it'll retail for a minimum of 9000 yen over there , possibly even over 10,000 yen. It'll sell atleast a million copies which means 10,000,000,000 yen in revenue. That's roughly 100 million USD revenue , some of that goes to the retailers but square will likely see 60% of it which means they'll need to sell atleast another million to really break even on the investment. It's a giant complicated bunch of BS.