Compositional etymology, never appearing in full in our sources. The main version of Orion's Etymologicum only has the mention of the "intensive da-" but the second member has disappeared. The excerpta have a version in which σπάνις "scarcity" is replaced by its synonym πενία "poverty", which is not the intended etymon. The Gudianum has the correct etymon for the second member but does not mention the first member, the intensive da-. The combination of all these sources leads to the reconstruction of the etymology as Δαπάνη· δέοντος σπάνις ἤγουν ἐλάττωσις (from the Gudianum).  ἔγκειται τὸ δα ἐπιτατικόν (from Orion, delta, p. 49). This yields *δα-σπανις, from which δαπάνη is obtained by dropping of the /s/. In an iotacizing state of the language, the ι of σπάνις and the η of δαπάνη could be identified, which made the etymology easy.