Buy low, sell high. The difference is called gross margin.
We can talk about gross margin in terms of percentage. If you buy something for $75 and sell it for $100, then your gross margin is 25%. (Your “markup” is 33%)
We can also talk about gross margin in terms of dollars. If we sold 100 units for $100 ($10,000 in revenue) and our gross margin was 25%, then we have $2,500 in gross profit.
We run the rest of the business on those gross profit dollars. We have to pay all our other expenses out of it.
Do you have enough gross profit %.
Do you have enough gross profit dollars?
To get more gross profit dollars, you have to increase your gross margin and/or sell more units.
Which is more doable?
As an accountant or just someone who can appreciate the art of the operations of a business, gross margin is where it is at. It is a continuous dance between growth and efficiency. Growth leads to set the level; efficiency follows to push profits to their highest, followed by growth when ready, followed by efficiency. One without the other is going to lead to lost profits.