iPhone 11 PM - earpiece speaker issue

Hi! Was planning to sell my iPhone 11 PM since upgrading na ako. But recently i noticed parang super hina na nung earpiece speaker ng phone ko, I can barely hear yung kausap ko sa phone kaya need magswitch to speaker phone.

Hm kaya repair nito? Pa-repair ko ba before selling or sell ko na lang na defective? Malaki ba katas nun sa price? And around how much na lang kaya siya mabebenta if ganun? Battery health 74%

Thank you.