In 2017, LEGO released 6 Friends Summer sets, all of these sets have been retired. For that year, the total price of all retail sets cost $186, today those sets are valued around $222, a growth of 19%.
Most valuable 2017 LEGO Friends Summer set
41317 Sunshine Catamaran $69.99
Highest growth 2017 Friends Summer set
41306 Mia's Beach Scooter +149.55%
Most owned 2017 Friends Summer set
41313 Heartlake Summer Pool
6 sets

30401 Pool Foam Slide

Theme / Subtheme Friends / Summer
Year 2017
Pieces / Mini-doll figures 40 / 1
Availability Retired
30401 LEGO Friends Pool Foam Slide
Retail $5.99
Value $12.76
Growth  +113.0%
Annual growth 5.3%

41306 Mia's Beach Scooter

Theme / Subtheme Friends / Summer
Year 2017
Pieces / Mini-doll figures 87 / 1
Availability Retired
41306 LEGO Friends Mia's Beach Scooter
Retail $9.99
Value $24.93
Growth  +149.5%
Annual growth 6.2%

41313 Heartlake Summer Pool

Theme / Subtheme Friends / Summer
Year 2017
Pieces / Mini-doll figures 589 / 2
Availability Retired
41313 LEGO Friends Heartlake Summer Pool
Retail $49.99
Value $60.00
Growth  +20.0%
Annual growth 3.6%

41315 Heartlake Surf Shop

Theme / Subtheme Friends / Summer
Year 2017
Pieces / Mini-doll figures 186 / 1
Availability Retired
41315 LEGO Friends Heartlake Surf Shop
Retail $19.99
Value $22.00
Growth  +10.1%
Annual growth 1.5%

41316 Andrea's Speedboat Transporter

Theme / Subtheme Friends / Summer
Year 2017
Pieces / Mini-doll figures 309 / 2
Availability Retired
41316 LEGO Friends Andrea's Speedboat Transporter
Retail $29.99
Value $31.93
Growth  +6.5%
Annual growth 1.4%

41317 Sunshine Catamaran

Theme / Subtheme Friends / Summer
Year 2017
Pieces / Mini-doll figures 603 / 3
Availability Retired
41317 LEGO Friends Sunshine Catamaran
Retail $69.99
Value ~$69.99