Does posting the link for a games purchase site at the resource page count as Advertising? A game I'm running do have some illegal versions, and if possible we want a non-pirated version to be used in runs. So, is it OK posting the links for the official page where you can purchase it or do I brake any rules?

You break site rules if you post any links to pirated games. Nothing is said about advertising the games (after all, it is logical to want to direct runners to the game page). If you post links to official game page, or post links to games that are free anyway (browser games or itch.io, for example), it is perfectly fine.

Ok, I'll go with posting it. Thanks for telling me your take on it.