[1.2.336] Changed Guild Skills

I'd like to know if the cast (Skill) prices apply to everyone

They don't. When Spadow was playing around with the skills in KMST, I didn't receive any buff. All I even saw was the skills cool down timers reseting and starting.

Casting works (I'm assuming) like the family system, where anyone who wants to be a part of it has to be in the same map. The person casting the skill will have money taken out of their own wallet.