auzadventure

Hi community, I'm trying to understand the cost. If say I buy the ST Index at say 2600 the bid/ask is 2599 2601, does that mean that the cost of the index contract is $2 x 1 = $2 for 1 mini contract? At the same time if I buy the sti ETF at 2.70 then my brokerage is 0.1% minimum of $10. So for smaller accounts best to go with the index right? Is it better buy the index or the ETF?