www.toysetc.com.au/p/lego-star-wars-imperial-star-destroyer-6211.html
is far superior to
www.toysetc.com.au/hobbies-toys-games/lego/star-wars/imperial-star-destroyer-6211.html
The latter sounds very deep and would take ages to get indexed and recached.
I think the shorter URL is good and will be effective.
Change the /p/ to /toys/
I would also stick the product code at the end instead of the 6211 if possible. Thats what a lot of people search for - in my industry anyway.