We generally recommend the more authentic Bärenreiter urtext edition of the Mozart concerti (available here), even for young players first starting on this repertoire. However, for pure economy this classic Schirmer collection with all of the completed works in one volume is hard to beat.

Contents:

Concert Rondo in E Flat Major (K. 371)
Concerto No. 1 in D Major (K. 412)
Concerto No. 2 in E Flat Major (K. 417)
Concerto No. 3 in E Flat Major (K. 447)
Concerto No. 4 in E Flat Major (K. 495)