By default, the bundle price is not displayed as a sale price (i.e. the bundle’s compare at price is not set).
Merchants may choose to display a bundle sale price.
To do this: first override the bundle price (optional), then check the Track compare at price? option.
Click on Create Bundle or Update Bundle to finalize this change.
Once checked, customers would see the overridden bundle price as the sale price and the original bundle price as the compare at price.
To adjust the bundle’s compare at price (i.e. strike-through price), see: Adjusting bundle price and compare at price