I'm most certainly not looking at it just from a PD point of view at all. The $150+ million revenue in the early months from a PS3 GT6 would be split roughly 60/40 between Sony and PD (based on standard splits for a game sale), as such it benefits Sony more than PD.
Even if a PS4 GT title was still full price after a year (which I seriously doubt) it would not return as much potential revenue as a PS3 title (unless they can shift 70 million PS4's in a year).
I'm not sure even 5 million is a realistic expectation within the first few months, especially given PS4 will be out end of this year.
Honestly I think Gran Turismo is just one of the games that somehow made their way to every tenth person gaming library because of ...1. it's the most well known racing game, just pure reputation ...
and 2. cars just happens to be something everyone in the world can relate to and has buying power just because people want "a real" racing game, even though they suck at true driving skills... they buy it and play it here and there and never care to excel at improving their skill level thus loosing interest ... that's the only 2 reasons I can see how a rather simple racing game has sold such unbelievable amount
So going by GT5 10 million sales, I figure it breaks down to 3 catagories:
1. 1-2 million are pretty big enthusiasts who play all the time and have become addicted to being the most perfect they can and enjoy fun and satisfaction real racing competition brings.
2. 2-3 million are playing it sometimes, kind of know how to handle the hard to drive cars around tracks but haven't gotten to the point that keeps them coming back because it's too tough or not fun enough.
3. The rest bought it (or got it as a gift), play around, might have fun but never developed a real sense of the fun of being good at just racing cars properly.
^^ Warning! Based on my personal feeling. Not based on facts.
What does that have to do with this? I think these 3 categories speak to the way GT6 would sell either early on PS4.
1. "Almost certain" to upgrade to next gen asap.
2. Probably half would very much consider upgrading to PS4 asap.
3. Wouldn't make a difference
In case of late PS3 release:
1. All will buy
2. Almost all will buy
3. Few will buy
Nobody knows how many PS4's will be floating around the world after a year or so, but I bet it will sell well. The point is, the more games there are the easier high sales targets will be possible.
Nor does it help recoup development costs for the PS4 as much as a PS3 title would. Which would you rather have 60% of 150+ million or of $6.5 million, because that's the difference you are talking about in the first few months alone (and these are NOT based on GT6 on the PS3 selling 10 million, rather they are based on 5 million).
Sony and PD both will benefit far more financially from a PS3 GT title than they ever would from a PS4 launch GT title, now they may be willing to write that off, but personally I find it unlikely.
Not quite sure how you came to these numbers, but anyway I think it would just be more speculation if I were to counter that with my revenue theories..
Will it be good and worth $60 is a question that should be asked of any title, on any platform and would apply just as much regardless of it being on the PS3 or the PS4, yet oddly you assume it only needs asking of a PS3 title?
From a logical financial point of view a PS3 GT6 will bring in huge revenue from the existing user base (and could also be supported by DLC) and allow two years for a user base to establish on the PS4 and for PD to fine tune a GT7 release. That is, from a financial point of view by far the most logical view.
Again I feel a solid overhaul of GT5 would be very good. GT5 Spec III for $20 or $30, hold all the content they've produced over the last years for PS4 and boom!! best racing game on the market!
(online aside of course).
