Olback touched on it - Price with the Aussie Dollar vs the US and UK is a vital part. I know that competeing on this would be retail suicide so you need to offer a better service IMO.
Price will always be a factor so dropping a % of the margin to get closer to the international price would help.
Product wise, for board games you want a wide range - not just for gamers. I know my wife keeps an eye out for family games or for the kids so you need to have a nice wide net. The same goes for a shop front.
Specialist TTG is a tough one - going to the privateer press/Wyrd etc and stocking the full range plus having a couple of 3x3 and 4x4 tables might help in keeping the shop front open... but again, price needs to be keen and the service needs to be top notch - gamers are Fickle!
I have seen a couple of stores come and go over the years - you need to ensure a constant promotion and advertising program is in place. People need to know where you are and what you do. Radio, catalogue and internet are all cheap media to use.
I actually have spent 15 years in the media and marketing areas so if you need any help sing out!