A phenomenological approach is proposed that takes into account the nuclearity-dependent binding energy in a cluster to determine its influence on the earliest steps of the homogeneous nucleation process and to determine the limits of the metastability/supersaturation domain for the monomer-condensed phase transition. It appears that the temperature at which monomers and clusters M-n have equal Gibbs potentials increases with nuclearity n and that the transition temperatures from the monomer to the dimer and to the bulk, respectively, bracket this metastability domain.