Any particular reason for the choice of a diesel polo? I think driveaway you're looking at >$25k for base model in manual (66TDI) and >$28k for the DSG diesel model.
Don't think the Bluemotion ones are available in Australia... so it's quite a substantial premium over the non-diesel Polo (which starts at under $21k driveaway). IMO diesels aren't really worth it unless you're driving a big car or something which will genuinely benefit from efficiency of a diesel engine.