So one CoE re-entry scroll costs 140 NC coin in BCM, but you can re-enter CoE by using 80 lunas in game, which costs you 80 NC coin (normally). BUT there is a bonus in luna purchasing at the moment which is +10% in small purchases and go up to 20% in bigger bundles so lunas cost less than normally now making it even more affordable to re-enter CoE using lunas instead of the scrolls.
Re-entry with lunas gets progressively more expensive with the most expensive is the 140 luna... but with the bonus in purchases this is still cheaper than 140 NC coin.
Lastly I am not sure anyone is using re-entries to get more coe runs when you can simply use a lakrum geared lvl 80 alt char to get in there 4 free times and simply take the manastones (which everyone is after) and broker-trade them to your main.
If NCWest wants to make money, they better put CoE bonus entry scrolld like 30 NC coin or something then people might buy them and NCWest might make a tiny profit. Because I am not sure anyone would ever waste any money on a coe re-entry with this RNG in gem rewards and price to re-enter.