Ecological considerations punctuate the indisputable benefit arising from “green bioplastics” like polyhydroxyalkanoates (PHAs) as alternatives to common polymeric materials. The widespread commercialization of PHAs as replacement for petrol-based packaging materials is to a high extent limited by their production costs. The major share of these expenses is caused by the raw materials required for the biotechnological production of these polyesters. Thus the work at hand summarizes recent advances in cost-efficient PHA biosynthesis by the application of cheap and easily available substrates. The exploration of novel carbon substrates is concentrated on surplus whey lactose from dairy industry and crude glycerol liquid phase from the biodiesel production. As alternative nitrogen sources for biomass formation, meat and bone meal, grass juices and several protein hydrolysates are pointed out. Recently, the production of high-quality copolyesters from unrelated substrates was described for several wild-type microbes together with attempts to elucidate the metabolic background. Enhancements in different downstream processing strategies are discussed, comprising the direct extraction of PHA from biomass, the digestion of residual cell material and the disruption of osmophilic cells in hyptonic medium. The different innovative steps in PHA production are addressed together with their economic impact.