FYI it's 3,000,000*0.009 + 7,000,000*0.004 to calculate your cost base = $55,000.
Then divide that by your total number of shares (10,000,000) to give your price per share ($0.0055 or 0.55c).
I'm a little concerned you want to invest over $50k here and can't calculate that, but I'll take you at your better nature and assume arithmetic just isn't your forte. Tell you what if PRL comes off you can tell your high school maths teacher you did amount to something after all!
