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 $56, a growth of 81%.
Most valuable 2015 LEGO Classic Baseplates set
10699 32x32 Sand Baseplate $25.00
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 $25.00
Growth  +212.9%
Annual growth 6.3%

10700 32x32 Green Baseplate

Theme / Subtheme Classic / Baseplates
Year 2015
Pieces 1
Availability Retired
10700 LEGO 32x32 Green Baseplate
Retail $7.99
Value $15.94
Growth  +99.5%
Annual growth 9.1%

10701 48x48 Grey Baseplate

Theme / Subtheme Classic / Baseplates
Year 2015
Pieces 1
Availability Retired
10701 LEGO 48x48 Grey Baseplate
Retail $14.99
Value $15.00
Growth  +0.1%