Im not exactly sure what your question is...?
Trades at 0.5c will only happen if there are sellers at that level. Just cause there are people willing to buy 80-odd million units doesnt mean that any trades will actually occur. It's a market, trades occur when buyers and sellers meet.
If you have a buy order at 0.5c you will be placed at the back of the que and it might take a long time before you actually get your 0.5c shares.
