In 2015, LEGO released 3 Classic Baseplates sets, all of these sets have been retired. For that year, the total price of all retail sets cost $31, today those sets are valued around $60, a growth of 94%.
Most valuable 2015 LEGO Classic Baseplates set
10699 32x32 Sand Baseplate $27.37
Most owned 2015 Classic Baseplates set
10700 32x32 Green Baseplate
3 sets

10699 32x32 Sand Baseplate

Theme / Subtheme Classic / Baseplates
Year 2015
Pieces 1
Availability Retired
10699 LEGO 32x32 Sand Baseplate
Retail $7.99
Value $27.37
Growth  +242.6%
Annual growth 6.8%

10700 32x32 Green Baseplate

Theme / Subtheme Classic / Baseplates
Year 2015
Pieces 1
Availability Retired
10700 LEGO 32x32 Green Baseplate
Retail $7.99
Value $17.12
Growth  +114.3%
Annual growth 10.0%

10701 48x48 Grey Baseplate

Theme / Subtheme Classic / Baseplates
Year 2015
Pieces 1
Availability Retired
10701 LEGO 48x48 Grey Baseplate
Retail $14.99
Value $15.66
Growth  +4.5%