There wouldn't be a "cheapest version" as a large percentage of most games see the majority of its sales in the first week where the price is the same.  Of course there are many other factors, but if someone has multiple consoles, it will definitely go to the one that "looks best."  

Also, if it were a multi-platform title to begin with, you wont have to "buy two systems."  This isn't about buying systems, it's about buying software.  Sales do NOT support your theory, by the way.  Simply having the main franchise sell more than a spin-off does NOT mean that it's stupid to make.  Spin-offs are usually (or almost always) cheaper to make given that you already have assets in place after making the main game.  it may still be more expensive than porting, but it is a much better way to get better sales on a system that isn't as powerful.  

edit: I will make it clear here that I do not mean to make these as absolutes as there will always be those exceptions, but as a general rule this is how it would be.

I think you misunderstood me ;)

I was meaning releasing a game on X as an exclusive can give the game more sales than if it was released on X and Y. Thanks to fanboys, exclusive titles get way more attention than multiplats. I was also only talking about smaller selling indie titles though. With big huge games like AC they'd lose a lot of sales going exclusive.

Didn't they just release that on PS3/360/PC because it sold so poorly?

Oh, yes. I did misunderstand you then!  sorry. I agree, except maybe, Nintendo needs to bring out a game that utilizes the gamepad and wiimote combo in an innovatiive way to pave the way for other titles to use a similar set up. That way they can just make really good use of the gamepad and wii motes without changing the game too much. I like what indies have been doing with the gamepad, games like Unepic make great use of the touch screen.

I buy a lot indie titles on Wii U and xbox live, I have a few on psn also. So far I am very impressed with some of the stuff indies have put out so far. I hope to see more quality titles come to Wii U, I think I have every indie game available on Wii U currently. 

Why you guys a are defending the idea of a downgrade port when you could defend a idea of a totally new experience to each of your consoles? I'm sorry if will cost more to developers, but i want a game that take full advantages fo the hardware i own. Its not my job see if the game will break even. Let this to publisher think about.

The OP has an EXTREMELY valid point, especially when it comes to such niche exclusives in Ninty's camp...

More like they just released it on PS3/360/PC because they could. Who knows what their original sales expectations were for that game.

I just thought it was funny that the OP used Assassin's Creed as an example, since it basically wound up describing Liberation, aside from that being on Vita rather than Wii U.

Maybe publishers would rather support Sony's struggling handheld than Nintendo's struggling home console. I don't think it matters. Even when they sell well, this sort of exclusive spin-off rarely stays exclusive. Dead Space: Extraction, Resident Evil: Revelations, Castlevania Mirror of Fate, etc.

For third parties, developing exclusive titles for a single console can still be viable, but not as spin-offs of big franchises. It doesn't make busniess sense to sell Assassin's Creed spin-offs to an entirely separate market from the main series when you could be making and selling those games directly to existing fans.

Well to its credit, it's the second best selling game on the Vita.

I completely agree. The Wii U can do so many things the PS4 and XBO can't do. The PS4 can do things the Wii U and XBO can't do. The XBO can do things the PS4 and Wii U can't do. Devs should be playing to those strengths. I was playing AC4 on my Wii U, and it felt like a depressingly Playstation experience. Then I played Deus Ex on my Wii U, and it felt right at home. There used to be a time where multi plats felt different. Now they just look different.

Let the PS4 be the console with the best graphics for multi plats. Let XBO be the console with with the best Kinect integration into multi plats. Let the Wii U be the console with the most unique multi plat experiences. Play to their individual strengths, not just the PS4's.

Every Wii U FPS and some TPS should be advertised with Wii Remote support. Games like Watch_Dogs should have almost invasive amount of Gamepad support and that should be ADVERTISED. Not just inventory and maps either. Hacking was one of Deus Ex's highlights. Take pictures in the game world using the gyroscope in the gamepad. Play cell phone touch games on your cell phone. Give the gamepad to a companion while you use a pro controller and use the gamepad as the companion app. So many possibilities.

Wasn't the Wii basically this?

Resident Evil on-rails shooters vs. RE5/6 on the PS3/360?

Exclusives like Red Steel 2 and COD was also usually different on the Wii.

Fact is usually a "spin off" is not as good as the real thing and while it's a fun fantasy to think developers can make high budget versions of each game different for each console ... it's also a pipe dream. No one has that kind of dev resources, it's easy to say "gimme a big budget exclusive game for my console of choice!" when you have no skin in the game, kind of a different story if was your own business and your own money and your job on the line.