Sure you are paying for the brand name, but I don't know many girls who would turn down the blue Tiffany box
I have a couple of T&C items, the quality isn't bad, but if you want to get something more fancy for the money you are forking over then I wouldn't go with T&C.
Does your gf wear a lot of silver? As I wouldn't get her something silver if she only likes to wear gold.
Personally I don't really like the style of that bracelet, but I don't really know your gf's taste, she might love it. One thing to think of when choosing the style is does she normally wear "chunky" bracelets, or something more simple/streamlined. I know some girls don't like wearing something too heavy on their wrists, especially if they have small wrists.
Sorry I don't have any recs on Brisbane jewelers, I'm sure others can advise.