The current system of Skilling Points just feels too simple and easy in my opinion - I feel this could be scrapped altogether and skilling points removed from the game. The difference in points gained for Easy, Default & Legend is really lame, and all accounts alike should have an equal opportunity to obtain the sets.
I've always liked the idea of the skilling outfits being obtained in a way that requires use of that specific skill - whether that be via a new set of skilling based achievements or as a randomly generated drop while performing an action in a certain skill.
A few examples I could suggest:
Runespan - Utilise the points to purchase the Runecrafter set.
Random drop chance from training a skill - such as smithing bars, blacksmith apron might drop.
Achieving 99 in a skill could guarantee 1 piece of the related skill outfit that the player does not own already.
Achievements based system with set milestones - EXAMPLE: Chop 10 logs, chop 50 logs, chop 1000 logs etc.
I think by the time a player reaches 200m XP in a skill, the player should have had the opportunity to obtain an outfit in its entirety.
I think it's important to allow all accounts the same chance at obtaining a piece of a skilling outfit, and for this reason feel they be untradeable so a player has a sense of Accomplishment when obtaining a piece.