I'm kinda not surprised they're porting the game to the 3DS. I mean it'd be a good fit.
Hyrule Warriors on the go? Why not? I mean the Vita has a Dynasty Warriors game so why shouldn't the 3DS have a competitor? Especially since Hyrule Warriors is a pretty good game. I do hope that you can transfer progress from one game to the other and vice versa. Otherwise it kinda knocks it down a bit because in this day/age there really isn't a reason why save data can't/shouldn't be able to transfer somehow.
Nintendo games take a long time to drop in price. And buying used doesn't save you much at all. (Maybe $5 at most.) So it's almost worth just buying new.
Still, I'd recommend buying the game. It's pretty fun. (I'd love to see an online co-op mode added though.)
Sorry, I should have been a bit more clear. Used in stores only saves about $5.
Online is an entirely other matter.
I tend not to even look online simply because whatever I'd save in original price just gets jacked up by shipping costs and import charges. I mean if the game is $30 US plus $10 for shipping and then another $10 for import fees the game already costs $50 US. Which I then have to convert to Canadian dollars, which raises the price by basically 20%. So a $30 game ends up becoming $60 afterall. And for all that effort, it's just easier to either pay for the used copy (from a store like gamestop) for $5 less or buy new for ~$15 more (over the $60 price mentioned above).
Perhaps in the US buying online saves you money, but in other countries? Not so much.