Mr Alagna is a professional dealer, consultant, and numismatic expert. In this role, he has carried out numerous appraisals and consultations with law enforcement agencies and Lawyers in court and as a Judge's Technical Consultant. He has cataloged and appraised coins on behalf of several Italian superintendencies and museums.
A member of NIP (Numismatici Italiani Professionisti) since its founding, he has served as Secretary, Vice President and currently holds the position of President. He is a member of RE.N.N.P.E (National Register of NIP Expert Experts), a member of A.I.S. (Appraiser International Society) and the Italian Numismatic Society. He is an A.N.T.I.C.O. (National Association for the Protection of the Gold Sector) chartered professional. He collaborates as a consultant for the Public Auctions of Numismatica Crippa srl Milan and for Cambi Genoa Auction House. He has to his credit various publications and articles pertaining to numismatics, particularly Sardinian and House of Savoy.