The Prices view in Sc Catalog inteface includes a field called Margin/Coeff, showing the margin value/percentage on each of your product.
The margin is calculated automatically by applying the formula you would have chosen in Sc Settings (Tools menu):
You can then easily control margins and eventually adapt product prices according to the margins.
To do so, you can run a csv export, followed by a csv import to modify product prices. Please refer to this article for more detailed information.