Cheaper brokerage for small investments

"Potentially even cheaper brokerage if feasible." "The ability to invest in smaller regular periods using auto invest but at at an ultra low cost % trading fee (0.05%) all the way down to smaller trade/investment amounts. E.g $500. Once you have some more scale - could this be achieved by pooling trades from multiple users at least for a small number of ETFs? E.g VAS, VGS, A200." "The lower the barrier to entry commission-wise and minimum investment amount-wise, the more I lean towards that platform. Right now, even though Opentrader is not offering automatic investing, the $5/trade for up to $2,500 really made me think hard, because I can invest twice as frequent with Opentrader and have more time in the market to maximise the chance of quicker compounding."