KoH is worth 288000 Summon Points .. Put your mouse pointer above your Runes and you'll see how much they are worth if you sold it into Group Points then do the math .. not that hard .. 1 set of 8s and 2 sets of 7s is not enough for 288000 btw ..

When I got KoH, I had 2 lv 8's, 4 lv 6's, and 24 lv 7's, which, if I recall correctly, was exactly the amount I needed (288,000), though I still needed to do the shop resets manually (I ended up getting all 80 frags at once when I got him, I remember losing 3-4k power. Which kinda hurt, but I have no regrets.)

i lost 3-4k bp in total when i sold my runes, but i didn't sell them all at once. i sold them slowly over a period of time so that my power loss wouldn't be so sudden. like, i capped my bp at 90k, and whenever it exceeded 90k, i took it as a chance to sell runes until my bp went down to 90k again. took me 3 weeks to save and redeem all 80 frags.

personally i don't see the point in selling runes all at once. it's not like you can redeem all 80 frags at once. even worse, the huge bp drop just won't help against people who are steadily growing. also it just looks really ugly lol. i also used this method to hide the fact that i was buying koh frags from the other people in my server.

I just stopped at all level 8 runes on 1 of my summons and left the 2 summons at level 7 runes. I then sold all runes I got. But when I was having 2nd thoughts on selling my runes before, all I did was remove the runes from the summons and you will see how much power you will lose if you sell them.