In 2013, LEGO released 2 Power Functions sets in the subtheme Accessories, all of these sets have been retired. For that year, the total price of all retail sets cost $39, today those sets are valued around $116, a growth of 297%.
Most valuable 2013 LEGO Power Functions set
88004 Servo Motor $85.83
Largest 2013 LEGO Power Functions set
88003 L-Motor 1 pieces
Theme / Subtheme Power Functions / Accessories
Year 2013
Pieces 1
Availability Retired
88003 LEGO Power Functions L-Motor
Retail $13.99
Value $29.78
Growth  112.9%
Annual growth 6.5%
Theme / Subtheme Power Functions / Accessories
Year 2013
Pieces 1
Availability Retired
88004 LEGO Power Functions Servo Motor
Retail $24.99
Value $85.83
Growth  243.5%
Annual growth 18.1%