I'd pay 60 dollars for it. Other people would pay 60 dollars for it. I can't really think of any field of meaning for "worth" where "Yes" is not right for me. I love the concept of this game, I mean if it happens to be rubbish then no, of course it's not worth 60 dollars. But it looks like it will be a pretty decent game, certainly one worth 60 dollars, so long as it's not executed poorly.
Well worth is a very strong assumption. I personally believe that more than half the game market isn't worth it's market price of $60 yet game companies price it anyway because they can. A perfect example of costumer mistreatment is EA. EA would release broken games like Battlefield # (most of them are buggy at release), Assassin's Creed Unity, etc. They release these broken games at $60 and people can't even play it for a month. Is this right? No, but they do it anyway because they can. Nintendo has a better reputation for releasing games that actually work so they're already ahead of their competitors on that. In the end, I do say that it's worth $60 because hopefully people will get a working product with features and gameplay they expect and enjoy. In the end, if you love Mario for what it truly is, then you should buy it and hopefully enjoy it, making it worth the $60 price tag. Thats all it counts in the end, right?
It is a level editor, that's it, that is the while game. Yes I think it looks awesome, but personally I think it should be 40 bucks brand new at most. 30 seems more fair. But I can see this being one of those hard to find games, so I have it now. It is still un opened though, because I will most likely return it. Unless of course someone can convince me it is worth it.