Very simple.  How much will you be willing to pay to buy one of the consoles?

can't say until i see what they have to offer but i think 399€ without anything special and 499€ if they are awesome in my opinion. 

i think i will buy one of both at release and the other console one year later but i have no clue which i will buy first.

Around 300 as i won't be getting this or others at launch. My PS3 still has year or two left in it.

If i were to get at launch $400 sounds fine depending on what it is. 

€499 for PS4
€399 for Nextbox

£300, maybe 400

Depends on what games they offer. But I am willing to pay exactly $0 for the right to play my own console online.

Really hard to say without them being announced, but as an Australian I would pay no more than $600 AUD, as that's what I'm expecting for launch here, though hopefully with our dollar being stronger it will be far less than the $999 PS3 launch here.

I'll have to wait for the 20th to see what the thing even is and what it offers. But 400$ seems fair. 500$ with BC.

I will buy a PS4, whatever it takes

i have plenty of dispossable income. i'm hoping for a $400 price tag (base model) so mass adoption isn't severely hamstring but i would personally pay up to $500 for a "deluxe" model with some awesome extras.

i put this in the perspective of i payed $500 for dinner and a show last weekend. a console will give me waaay more entertainment over the next 5-8 years.