i see the images were removed for possible inaccuracies. i can confirm on the second to last fight,it is 2 gem per hour to skip timer. i got one fight left, it takes 75 coins to claim the block with one fight left. i'll update/verify coin requirements as soon as i do the last fight in a few minutes.
after fight, 295 coins to claim.
after marauder chest, 300 to claim.
after legend essence, 305 to claim in order to reach last fights.
just waiting on last collection in a few hours for my last 600 coins. i only have 193 coins left right now....so it's possible i might be able to skip a fight to save on gems.
update (last fights):
after first fight, first timer is 3 hours 11 minutes 40 seconds...240 coins to claim entire block,or 12 gems to skip timer....so looks like 3 gems per hour to speed up....so i suggest if you are gonna gem it up,wait12 minutes to save 3 gems.