Getting offer updates on a property

[Rudy Ratner]

Whenever I ask my realtor to look into a property, sometimes he does not seem to bother replying because people have already made offers way above my budget. 

Is there a site (paid or otherwise) where I can get what offers have been made on a property? That way I dont need to keep bugging my realtor on those properties as I would have an idea of my competition. Is such a service available for non-agents?