Was the Dressrosa Arc inspired by the Alabasta Arc?
Well.. it is not stated anywhere by Oda himself (as far as i could search), but there is an ongoing rumor that the arcs in the New world are counterparts of their respective arcs in the beginning of the grand line. 

So, we have Dressrosa as the first big arc since the straw hats entered the New World as a counterpart to Alabasta and Punk Hazard as the New World's counterpart of Drum.

Despite the similarities, there is still no confirmation by any official source that Dressrosa was based on Alabasta.

Annex: List of similarities between Alabasta and Dressrosa