We know that Sony has lost a lot of money beacuse of ps3 prices cuts so I would like to understand how much ps2 is helping sony to reload its finances..

Probably quite a bit. ~$20-$30 per would be my guess. Maybe more if they are considering a drop to the $99 price point.

Hmm, good question. Sony has kept the $129 price point for an amazingly long time, while the hardware gets cheaper and cheaper (though not 30% per year for leading edge hardware, it's more like 10-15% a year for mature tech). My guess -- and this is only a guess, and probably wildly wrong -- is that they could be making as much as $40 on the hardware alone, though advertising, shipping and servicing costs mean actual profit is $20 on each unit.

That's a lot of money, considering the console still sells about 70k a week.

70,000 x $20 = $1,400,000.

They cant earn much because their game division is bleeding alot. After 2008 and the sales of ps2 have slowed down they be more screwed.