In 1975, LEGO released 6 Trains 4.5V / 12V sets, all of these sets have been retired. For that year, the total price of all retail sets cost $49, today those sets are valued around $3,810, a growth of 7653%.
Most valuable 1975 LEGO Trains 4.5V / 12V set
182 Train Set with Motor $1,356.44
Highest growth 1975 Trains 4.5V / 12V set
137-2 Passenger Sleeping Car +22886.24%
Most owned 1975 Trains 4.5V / 12V set
148 Central Station
6 sets

133 Locomotive

Theme / Subtheme Trains / 4.5V / 12V
Year 1975
Pieces 87
Availability Retired
133 LEGO Trains Locomotive
Retail $2.89
Value $610.95
Growth  +21040.1%
Annual growth 11.3%

134 Mobile Crane and Wagon

Theme / Subtheme Trains / 4.5V / 12V
Year 1975
Pieces 86
Availability Retired
134 LEGO Trains Mobile Crane and Wagon
Retail $2.49
Value $431.60
Growth  +17233.3%
Annual growth 10.8%

136 Tanker Wagon

Theme / Subtheme Trains / 4.5V / 12V
Year 1975
Pieces 83
Availability Retired
136 LEGO Trains Tanker Wagon
Retail $1.89
Value $172.20
Growth  +9011.1%
Annual growth 9.4%

137-2 Passenger Sleeping Car

Theme / Subtheme Trains / 4.5V / 12V
Year 1975
Pieces 82
Availability Retired
137-2 LEGO Trains Passenger Sleeping Car
Retail $1.89
Value $434.44
Growth  +22886.2%
Annual growth 11.5%

148 Central Station

Theme / Subtheme Trains / 4.5V / 12V
Year 1975
Pieces / Minifigs 293 / 5
Availability Retired
148 LEGO Trains Central Station
Retail $19.99
Value $804.05
Growth  +3922.3%
Annual growth 7.7%

182 Train Set with Motor

Theme / Subtheme Trains / 4.5V / 12V
Year 1975
Pieces 369
Availability Retired
182 LEGO Train Set with Motor
Retail $19.99
Value $1,356.44
Growth  +6685.6%
Annual growth 8.8%