M-Tron (also written M:TRON) was a LEGO Space subtheme released in 1990 that consisted of 8 sets where the M-Tron were depictedas a rescue and repair faction in all LEGO catalogs except for the United States, where they are described as a mining faction. M-Tron was also the last space theme to carry the LEGOLAND banner and was changed to just LEGO System.
M-Tron consists of 9 sets that ran from 1990 to 1991. As of today,
6923 Particle Ioniser is the most valuable M-Tron set with an estimated new/factory sealed value of $3,287.
Summary
Space M-Tron Beacon Tracer set 6833 was released in April 1990, retailing for $3, but has since been retired. New, unopened Beacon Tracer sets are valued at $84, while used sets can be found for $10.
Read more