Trying to figure out how much my Tarmac SL6 Tiagra is worth

Hi all,

I have been using my SL6 for some time and unfortunately had someone jump out in front of me causing me crash. Long story short the frame is cracked at the seat stay and I am trying to debate whether I should repair it and sell it and what a fair price would be.
I will most certainly not be selling the bike without it being repaired.