ApiDrop lets you change your sale price directly on your ecommerce platform.
When a product has been synced and copied on your platform, you can change everything you want (but not the SKU or it will not be recognized anymore).
So, after the first sync, you can assign the price you want directly from your store admin panel, without doing that in ApiDrop.
The most important thing, to be sure that your prices will not be overwrite, is that your Sync mode is set on "Sync Only Stock & Cost" .
This way, your edited price will not be modified during future syncs.
What if you have many products and you want to do that automatically?
You can use the Repricing tool that will auto-calculate the new price based on your desired markup, here you can find a detailed guide.