I don't see point in increasing endurance/mind since you get scaled costs anyway.
It may be not the only way, but if you want to unlock triple orgasm passive, you need to rise your Mind stats.
The amount of pleasure Karryn can hold by using Resist Orgasm is "100 + mind*2", so you need at least around 95 Mind to experience triple orgasm.
and the triple orgasm passive "Brain Melting Triple Combo Orgasm" is OP. it surpasses your surrender.
you can use accessories and titles to reach upon 100 Mind. so around 75 stats is enough.