In 2008, LEGO released 3 Exclusive sets across 3 subthemes, all of these sets have been retired. Subthemes for that year included Employee Gift, FIRST LEGO League, and Minifigure Collection. For that year, the total price of all retail sets cost $93, today those sets are valued around $1,124, a growth of 1108%.
Most valuable 2008 LEGO Exclusive set
2008 Heart $690.05
Highest growth 2008 Exclusive set
9699 FIRST LEGO League Challenge 2008 Climate Connections +401.84%
Most owned 2008 Exclusive set
852331 Vintage Minifigure Collection Vol 1
3 sets

2008 Heart

Theme / Subtheme Exclusive / Employee Gift
Year 2008
Pieces 92
Availability Retired
2008 LEGO Heart
Value $690.05
Annual growth 21.0%

9699 FIRST LEGO League Challenge 2008 Climate Connections

Theme / Subtheme Exclusive / FIRST LEGO League
Year 2008
Pieces / Minifigs 778 / 12
Availability Retired
9699 FIRST LEGO League Challenge 2008 Climate Connections
Retail $75.00
Value $376.38
Growth  +401.8%
Annual growth 9.4%

852331 Vintage Minifigure Collection Vol 1

Theme / Subtheme Exclusive / Minifigure Collection
Year 2008
Pieces / Minifigs 21 / 5
Availability Retired
852331 LEGO Vintage Minifigure Collection Vol 1
Retail $17.99
Value $57.30
Growth  +218.5%
Annual growth 7.2%