Hi,

For acoustic piano, there're plenty of shops which buy used acoustic piano. Wondering if anyone know any shop which buys used digital pianos?

digital pianos have very low value

sell it off mudah.com

nope...used digital piano have no value. You can post selling them in online sites. I think kids new to learning pianos would buy. Parents would not want to invest into real piano until they are sure the child is serious about learning them.