I've tried to get a decent balance of cost versus performance. On the plus side, everything except the PSU and optical drive are available locally, and the cost of buying locally isn't too much higher than shipping from the US.
Edit: Echo's build Mk 2. Swapped out the PSU and optical drive for similar items in stock locally. Because the USD to AUD exchange rate is sheer murder I have decided to buy everything here; prices after international shipping costs make the difference not worth the extra hassle.
Edit 2: Build Mk 3. Swapped HDDs for a faster model.