Several studies support the environmental sustainability of relay intercropping of cereals with subsidiary legumes. However, the question whether the relay intercropping is also sustainable from an economic point of view remains to be answered. The objective of this study was to make an economical evaluation at cropping system level of eight different legumes species. In this study these legumes were evaluated taking into account the impact of the legumes on the co-cultivated wheat and on the following summer crop, forage sorghum. We assumed that annual, annual self-seeding, and perennial legumes work differently and bring different margins, allowing to identify the most cost-effective ones. Our hypothesis was therefore that the cost due to the relay intercropping can be balanced by the ecosystem services it provides, if suitable legumes are chosen.