In 2015, LEGO released 4 Star Wars Promotional sets, all of these sets have been retired. For that year, the total price of all retail sets cost $80, today those sets are valued around $826, a growth of 932%.
Most valuable 2015 LEGO Star Wars Promotional set
Tatooine Mini Build $396.44
Most owned 2015 Star Wars Promotional set
Poe's X-Wing Fighter
4 sets

Tatooine Mini Build

Theme / Subtheme Star Wars / Promotional
Year 2015
Pieces / Minifigs 178 / 1
Availability Retired
LEGO Star Wars Tatooine Mini Build
Retail $39.99
Value $396.44
Growth  +891.3%
Annual growth 12.4%

San Diego Comic-Con 2015 Dagobah Mini Build

Theme / Subtheme Star Wars / Promotional
Year 2015
Pieces / Minifigs 177 / 1
Availability Retired
LEGO Star Wars San Diego Comic-Con 2015 Dagobah Mini Build
Retail $40.00
Value $384.98
Growth  +862.5%
Annual growth 12.5%

Wookiee Gunship

Theme / Subtheme Star Wars / Promotional
Year 2015
Pieces 41
Availability Retired
LEGO Star Wars Wookiee Gunship
promotional
Value $21.28
Annual growth 6.8%

Poe's X-Wing Fighter

Theme / Subtheme Star Wars / Promotional
Year 2015
Pieces 27
Availability Retired
LEGO Star Wars Poe's X-Wing Fighter
promotional
Value $22.88
Annual growth 8.8%