In 1975, LEGO released 6 Trains sets in the subtheme 4512V, 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 $3,986, a growth of 8012%.
Most valuable 1975 LEGO Trains set
182 Train Set with Motor $1,429.70
Highest growth 1975 Trains set
133 Locomotive +25272.32%
Most owned 1975 Trains 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 $733.26
Growth  +25272.3%
Annual growth 11.5%

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 $406.48
Growth  +16224.5%
Annual growth 10.5%

136 Tanker Wagon

Theme / Subtheme Trains / 4.5V / 12V
Year 1975
Pieces 83
Availability Retired
136 LEGO Trains Tanker Wagon
Retail $1.89
Value $205.43
Growth  +10769.3%
Annual growth 9.6%

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 $316.48
Growth  +16645.0%
Annual growth 10.6%

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 $895.08
Growth  +4377.6%
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 $1,429.70
Growth  +7052.1%
Annual growth 8.7%