I have played JRO for 2 months already, I have some good examples about OCP gears:
In JRO: a +9 abyss =3.2B, and in JRO, 1B = about 300-350usd
Does it kill gloom card(8B in JRO)?
No, JRO has many powerful armors, something like an armor with Hawkeye enhancement(yea it is expensive, about 3.5B), JRO's formula is close to 1.0 so bonus ATK from every 10 dex is astonishing;
you could always find an powerful armor with gloom card, and together they are much much better than just an abyss dress.
So you see that in JRO ocp items won't totally replace in-game items; it is just an optional way for players to approach the endgame. If you are a long time JRO player who has gloom card, do you really feel bad about abyss dress? Not really.
How about in IRO? Maybe the best is +14 abusive with double S3/D3? How much is +14 abusive+double S3/D3+gloom card? I don't think those gloom card owners would be happy to see abyss dress in ocp box.
Another problem is that may OCPs have special OP effect when they are +10, in JRO, a 100m headgear can be sold at the price of 6B when it is +10.
I think cost of +10 in JRO is close to +15(lv4 weapon) in our server.
OCP is a good idea, but they all need to be adjusted according to IRO's environment