Sale Price
Marketplace Connect supports attribute mapping of price and sale price to meta fields. This enables the seller to control both price and sale price in a discrete way without referencing the core shopify pricing fields.
Create a meta field in Shopify
Set your prices in that metafield then you can map this via Attribute Mapping in the Marketplace Connect app.
Discounts
We offer the option to apply discounts via the app through the offer pricing feature. If the list price differs from the offer price, Target will display it as strikethrough pricing. In Shopify admin, using the 'compare at price' will automatically publish to Target as the ListPrice when we sync.
No additional steps are required; this process is automatic as long as the sale price is less than the list price.
Alternatively prices can simply be set via Single Edit or Bulk Edit in the app.