Ah, welcome to the amazing world of arcade sticks! Wow, arcade stick prices have actually been going up as of late, oddly enough. It's become harder to find new sticks... But anyways, unless you specifically want to DOA5 stick, I'd look around on places like ebay and the like to see if you can score one for around the $100 mark, which is about what I got my first one for. That said, if you're focused on the DOA5 one, it's a good stick, like you said it's got Japanese made sanwa parts, which is always a good start. Aside from that, unless you're getting a really cheaply made stick (and that Hori is not cheaply made), odds are the case for it is fine as well, meaning that if you want that stick, go for it.
Octo-gates are argued on by a lot of people, I personally bought an octo-gate, and it's NOT in any of my sticks. Ignore what anybody tells you about octo-gates being lame, if you like playing with them, that's absolutely fine, buuut, using an octo-gate makes it quite a bit harder to make diagonal inputs. With practice, it'll most likely become irrelevant, but, with practice, you'll be better on a square gate then you would with an octo-gate anyways. If you're playing a 3D fighter, like say Dead or Alive, typically diagonals are a big deal, and it being harder to make those inputs with the octo-gate sucks, trust me, I tried it. If you're playing 2D fighers, it becomes quite a bit harder to jump, so again, you're at a disadvantage. So my recommendation would be, stay away from an octo-gate because odds are you won't end up liking it anyways. If you do order the octo-gate anyways though, just get the insert from focusattack, you'll save a couple of bucks, since you'll never need to replace the actually plate.
