The cheapest american DBA program that I know is the one from Argosy, about 28,000 dlls. Still pretty expensive for a low tier university. The DBA from Charles Sturt is about 10,000 dlls US. I would expect the DBA from Charles Sturt at least to perform at the same level as the one from a low tier virtual university, but it seems that some people is bias against foreign degrees so some students prefer american degrees (even if they are expensive and from low tiers) for this reason.