I don't think sales are less generous due to greed, I think it's more the fact that companies are realising that so many people on PC will 'wait until it's on sale' for prices like £3 and it's hurting profit.
PSN has a sale on at the minute with similar price reductions as Steam has now, which is about fair I think.
But the marketplace is swamped with many thousands of games.
It's understandable that people will wait for sales... Many more games are bought than we will ever have time to play!!
One the one hand I've bought a lot of games for £3 that were worth a lot more, this is no doubt true. But I haven't forced them to lower the price that much.
And I've bought a shedload more games than I otherwise would, perhaps even spending more than I otherwise would.
Only now my money is shared around between a lot more companies, rather than less people getting £10+ each sale.
Is that better, worse, or simply giving more people a chance they otherwise wouldn't have to make a living making games?