I'm a little bit a lost with the price for multiple destination price.

I will travel to jakarta and on my way back home, my parents will come with me.
So our travel route will be
For me : gva - cgk and cgk - cdg route, economy class price is $14427
my parents : cgk - cdg and gva - cgk, economy class $1500

wth?? is there some mistake or error?