Bellamy, Carson, Sissoko, Crouch, Garcia were certainly not failures. Cisse wasn't a Benitez signing and Morienties was one of the form strikers in the previous season and just failed to develop. Keane was awful, and was sold promptly for the same fee he was bought for.
Most of the players Benitez signed himself that were then sold on were sold for a profit. The players that were sold for losses were Houlliers signings such as Cheyrou, Diao, Cisse, etc..
Your statement is just lacking any thought or context Fbarbes.
PS. Rafa didn't negotiate the transfer fee's. It was mostly down to Rick Parry.