It's really hard to say.
A high budget X360 game is around $20m. That includes most "blockbusters" - Call of Duty 4, Halo3, probably BioShock, Mass Effect, Lost Planet, Dead Rising, ect.
For a mid budget (I doubt Darkness and Overlord are in the high range, and are more likely mid-range), would probably be $10m on the initial platform + 10-20% dev costs to port to PS3, and maybe 5-10% to PC.
A low(er) budget game would probably be in the $5m range.
So using those values, you can assume (with around $40USD going to the dev/publisher):
High End: 500,000 Units + Marketing (which varies)
Mid-End: 250,000 Units + Marketing
Low-End: 125,000 Units.
Likewise, Wii would probably be just around 60% of that per title + marketing. So we'd get, assuming $34.00 per title:
High End : 353,000 Units + Marketing
Mid-End: 176,500 Units + Marketing
Low-End: 88,250 Units + Marketing
Now, of course, on the X360, you have the advantage of making some money off of DLC. Nearly every game has picture packs and theme packs. These can garner a bit of sales. Likewise, some games have expansion backs and add-on areas for $5-10 per unit. 70% of that goes to the pub/dev on the deal. So that lowers costs as well.
Now, for Marketing, that could really vary. Some games might have $250,000 for a marketing budget, whereas major games could have upwards of $5, $10, or more million dollars.
Back from the dead, I'm afraid.
