In 2010, LEGO released 3 Seasonal Halloween sets, all of these sets have been retired. For that year, the total price of all retail sets cost $6, today those sets are valued around $21, a growth of 243%.
Most valuable 2010 LEGO Seasonal Halloween set
40012 Halloween Pumpkin $7.73
Largest 2010 LEGO Seasonal Halloween set
40014 Halloween Bat 25 pieces
Most owned 2010 Seasonal Halloween set
40013 Halloween Ghost
3 sets

40012 Halloween Pumpkin

Theme / Subtheme Seasonal / Halloween
Year 2010
Pieces 18
Availability Retired
40012 LEGO Halloween Pumpkin
Retail $1.99
Value $7.73
Growth  +288.4%
Annual growth 9.1%

40013 Halloween Ghost

Theme / Subtheme Seasonal / Halloween
Year 2010
Pieces 18
Availability Retired
40013 LEGO Halloween Ghost
Retail $1.99
Value $6.40
Growth  +221.6%
Annual growth 7.8%

40014 Halloween Bat

Theme / Subtheme Seasonal / Halloween
Year 2010
Pieces 25
Availability Retired
40014 LEGO Halloween Bat
Retail $1.99
Value $6.37
Growth  +220.1%
Annual growth 5.4%