VGA is from videocard to monitor, not the power supply. I think what you mean is PCI-EX connector(6 pin or 8 pin). You will need a separate one for each videocard.
So, for example, if you have 6 GPUs and they each require a 6 pin connector, then you need six separate 6 pin connectors, you can't 'share' one between cards.
If you can afford six GPUs then you can afford a proper power supply.