Subject: pricing based on supplier price - by: msjs

I want a replacement for quickbooks which I hate and have been forced to use while a student. I want to sell liquid herbs which I mix. I buy them by the 500ml or 2.5lt bottle and mix say 20ml of one, 60ml of another, 110ml of another, and 15ml of the last one. Each one of these is fine as a line in the sales docket. But I'd like a price per ml automatically generated based on the price of the supplier plus my profit margin? Is this easily possible or should I look elesewhere? (I've narrowed my choice to 4 applications)