charge upfront before publishing post or page

Hi.

You can always “Award” a negative value for published content. If you do, each time a user publishes a post, he will loose points instead of gaining.

So you want to give points for draft posts or pending posts?

You could adjust the “Points for publishing content” hook to instead of awarding / deducting points for published content to deduct points for i.e. pending posts (posts submitted by contributors but not yet published) via the mycred_publish_hook_new hook.

Example: Change the hook to award / deduct points for pending posts:

add_filter( 'mycred_publish_hook_new', 'points_for_pending_posts' );
function points_for_pending_posts( $statuses ) {
	return array( 'pending' );
}

The above code will change the Points for publishing content hook so point will only be awarded / deducted for pending points. If you want both, you will need to create a custom hook that specialize in only deducting points from pending posts and not published.