In 2008, LEGO released 2 Mindstorms sets in the subtheme NXT, all of these sets have been retired. For that year, the total price of all retail sets cost $60, today those sets are valued around $137, a growth of 128%.
Most valuable 2008 LEGO Mindstorms set
RF ID Sensor $94.29
Largest 2008 LEGO Mindstorms set
Keyfob Transponder 10 pieces
2 sets

RF ID Sensor

Theme / Subtheme Mindstorms / NXT
Year 2008
Pieces 3
Availability Retired
LEGO Mindstorms NXT RF ID Sensor
Retail $29.99
Value $94.29
Growth  +214.4%
Annual growth 7.0%

Keyfob Transponder

Theme / Subtheme Mindstorms / NXT
Year 2008
Pieces 10
Availability Retired
LEGO Mindstorms NXT Keyfob Transponder
Retail $29.99
Value $42.47
Growth  +41.6%
Annual growth 2.1%