I didn't even want to buy a launch 3DS or Wii U. Both of those systems were too expensive and lacking critical features at launch. I bought a 3DS in 2012 for $160 and still haven't bought a Wii U. $250 is too much for a handheld in my opinion, I'd rather pay $200 or under. Likewise, $300 is pushing it for a console, that's probably the most I'd pay but I'd prefer $250 or under. As it stands, the Wii U has a couple of games bundled for that $300, so it's not bad.

Considering OP asked for a "mega powerful" console, I assumed he meant more powerful than the Xbox One was relative to 2013, which would mean more expensive than the Xbox One was in 2013, which I interpreted as $500+. If it was much less than that, it wouldn't really justify the annual payment plan. People have already shown that they are more than willing to spend $400 on a new console.

PS3 got a few games recently and has a few more coming, but NX isn't out yet and won't be for at least a year and a half, more likely two and a half years. I consider your suggestion that anyone who doesn't want to spend $400 or more on a new console should just buy a ten-year-old console instead as belittling as Don Mattrick's infamous "we have a product for people who don't want an always-online device, it's called Xbox 360" blunder.

It's especially unhelpful to a long-time Nintendo fan. Just buy a Wii or a 3DS instead? I already have those. I bought them for $250 and $160, respectively, and I have no interest in paying double or triple that amount for a game console, whether all at once or spread out over several years.

hmm, well I've always seen it that most people don't adopt new systems right away whilst theres still support on the ones they currently have and the ones that do don't mind paying a premium price. I guess its a bit different with Nintendo in that their gens don't cross over at all. A new systems arrival is the previous systems immediate death lol

would you feel more comfortable pay $400 for NX if it had as much third party support as the playstation4?

Useless info as we would never know if this would happen until it does. What would be better is a strong 1st party release offerings, and hype marketing. 

Its not infomation, its a hypothetical question ;)

Price I can agree with if the systems do not offer anything more than the ability to share software. If there is an updated version of the gamepad (720 display, ect) I can see the MSRP being around $300. 

As for upgrades every three years, it may be possible, but still something I don't really see. It may be like their New 3DS system, where the updated hardware may get some exclusives, but the majority of games would still be for both gens.... I don't know, as I said, this is hard to see for me. I think this will have a lot to do with the success of the New 3DS. I would be all for an add on (think 32X for the Sega Genesis) that allows for games to detect the device and add more effects to the game if the device is detected, but a whole new console would be a pretty big gamble. 

Well their is a history of people upgrading their consoles every few years.

Playstation-1995, PSOne-2000

PS2-2000, PS2 Slim-2004

PS3-2006, Slim-2009, Super Slim-2012

Xbox 360-2005, Xbox 360S-2010

The difference is that in this situation the new selling point wouldn't be the device being smaller/sleeker but that it has better performance.

It can get away with it, sure, but it would have to be one fricking amazing handheld to get me to spend that much for the hardware alone.