Using Best Offer NopCommerce Plugin , Login user can place bid on other user products and can also see all bids which is added by other user on same products.
After Install Best Offer Plugin , user can see two link at bottom of my account page like My Products & My Bids.
1) My Products : Using My Products link , User can see all products which is added by him. he can also edit or delete or new product add.
Also in Product List , use can see his product cost and highest bid amount on a particular product (other user can place bid on the product on product detail page) .
2) My Bids : Using My Bids Link , login user can see all bids which is place by him on other user's product.
On Product Detail Page at bottom , login user can see all bids on a particular product. he can also place a bid on product.
Each user can place only one bid on each product and user can not place bid on his product.