Refers to heavily discounted items used to attract customers, often sold at a loss to drive store traffic.
I lined up early to buy the bargain goods at the opening sale.
eye-catching goods; featured product
Highlights products prominently displayed to draw attention, not necessarily discounted.
This week's featured products are displayed at the store entrance.
This supermarket makes eggs its loss-leader item.
They launched the new product as a bargain loss leader.
We prepared some loss-leader items ahead of the sale.
お買い得 is a general term for a good bargain on any purchase, whereas 目玉商品 is specifically a store's promotional item meant to draw in shoppers.
目玉商品 is the explicit term for a featured bargain product, while 目玉 alone is a casual shortening used when the context already makes clear it's a product.