I played well over 100 hours of Left 4 dead, I preordered it and got it on release, it cost me £20, which at the time was about $35USD. That equates to around $0.35 an hour and the only reason I stopped playing was because my PC is being shit and I can't, I could easily play hundreds more hours of it.
The point is, they've taken left 4 dead and learnt what they did wrong with it, of course they could slowly drip feed us the rest of it through DLC but by the time it's all released it'll be hardly played anymore. I have absolutely no problem with buying Left 4 Dead 2 @ full price and I don't think anyone should.
They're redoing the entire game, it follows the same basic story, granted, but with the new special infected the game play and game dynamics will change massively. Take melee weapons for instance, they'll bring a while new feel to the game, adding them to the current Left 4 dead would break some other things, it would also change how we play it.
It's quite obvious that they're releasing left 4 dead 2 for the money, but Valve as a company don't care about money as much as a lot of others, they'd rather have happy customers and this is evident through the way they constantly update TF2, they don't have to but they do and it makes us more loyal to them - which is ultimately money, but there are easier ways to make more money.
tl:dr; stop moaning about it, $40 which is what the price will be... ish, is <4 hours work, 4 hours work for 100 hours gameplay is an excellent deal, there's games I've spent $40 on and played for about 20 minutes before I got bored.
