Yes, on Mercari, negotiation is encouraged, and buyers have the opportunity to make offers on items listed for sale. When you find an item you are interested in, you can click on the "Make Offer" button to suggest a price that is lower than the listed price. The seller will receive your offer and can choose to accept it, reject it, or counter your offer with a different price. This option allows for a back-and-forth negotiation, making it possible to agree on a price that works for both parties. However, it is important to be respectful and reasonable in your negotiations to maintain a positive shopping experience. Additionally, sellers may also choose to set their items as "firm," indicating that they are not open to negotiation. Always check the item description for any specific instructions or notes regarding offers.