Question: I'm looking for a browser extension that compares prices across different marketplaces to find the best deals on used items.

If you're looking for a browser extension to compare prices across different marketplaces for used items, Beni is a standout option. This AI-powered shopping assistant helps you find discounted prices on secondhand items from over 40 resale sites, with features like price comparison, resale deals aggregation, and favorites and alerts. Beni is free to use and supports over 2,000 retail sites, making it a comprehensive tool for sustainable shopping.

Another excellent choice is Karma, which not only offers price comparison but also automatically applies promo codes and cashback rewards at checkout. With support for over 100,000 stores and a user base of over 6 million, Karma can help you save 18% on average per order. Its features include price tracking, wish list management, and social media integration, making it a robust tool for enhancing your online shopping experience.

For a more data-driven approach, Penny AI provides price comparison and pros and cons analysis across many sources with just one click. Designed to make shopping more efficient, Penny AI can help you make informed and cost-effective choices by offering a detailed view of products' advantages and disadvantages.