In 2012, LEGO released 4 Seasonal Christmas sets, all of these sets have been retired. For that year, the total price of all retail sets cost $33, today those sets are valued around $90, a growth of 172%.
Most valuable 2012 LEGO Seasonal Christmas set
3300014 Christmas Set $49.99
4 sets

40034 Christmas Train

Theme / Subtheme Seasonal / Christmas
Year 2012
Pieces 82
Availability Retired
40034 LEGO Christmas Train
Retail $4.99
Value $11.99
Growth  +140.3%
Annual growth 4.7%

40035 Rocking Horse

Theme / Subtheme Seasonal / Christmas
Year 2012
Pieces 49
Availability Retired
40035 LEGO Christmas Rocking Horse
Retail $4.99
Value $8.21
Growth  +64.5%
Annual growth 2.5%

850503 Holiday Bauble

Theme / Subtheme Seasonal / Christmas
Year 2012
Pieces 3
Availability Retired
850503 LEGO Christmas Holiday Bauble
Retail $7.99
Value $19.58
Growth  +145.1%
Annual growth 5.3%

3300014 Christmas Set

Theme / Subtheme Seasonal / Christmas
Year 2012
Pieces / Minifigs 109 / 4
Availability Retired
3300014 LEGO Christmas Set
Retail $14.99
Value $49.99
Growth  +233.5%
Annual growth 10.2%