I think your time table is questionable. Within a year, a $60 game will generally be $30, and $20 or less a year after that. I don't think you have to get total price parity for a regional release. Fewer people in the privileged markets are going to bother seeking out the game in another region to save $5 or $10 than they are to save $40 or $50.

I'm struggling imagining who can afford the equipment to run 'the latest tech' but will not be able to afford a game that uses it. I strongly suspect 'the latest tech' is important mostly to the privileged markets.

You might be right about the marketing. A hit game will probably be just as profitable later; maintaining or growing its own hype. The bigger problem I think is for games that are flops. Companies probably want to sell as many copies as possible before word gets out; and greatly staggering releases will result in a lot fewer copies being sold as you suggest.