Are you talking about a domain on Godaddy listed at a price you prefer not to pay? Or are you talking about one that suggests you contact a broker to obtain?
Keep in mind, that the domain owner ultimately may be the best first contact. Even if privacy is enabled, the owner may have enabled messages to be sent to them. One caveat, though. If you start out at a very low price, the seller may not take you seriously. So try to be realistic and fair up front with an offer.
Compared to paying potentially 20% or more using the broker, you may do better in the long run.