Have a pile of rare souls, around 500. Not sure what to do with those, they've been sitting on the book of souls unopened for a while.

Opening 99 rare souls cost almost 2.5M gold; i already have all 4*-3* possible reward toons, and almost all 5* (except domino and dracula). Chances of a 5* are 1%, and hitting the toons I'm missing would be less than 0.1%.

If rewards for sacrifice were awakening materials (or awakening soul fragments), perhaps I'll consider opening these souls. Otherwise, I believe I'm dumping gold every time I'm opening 99 souls. Then you get epic fragments and souls: more gold dumped.
What do you guys normally do? let them pile up? or do you believe that sacrifice rewards compensate the gold lost?