The math is all that matters. According to the math of a Dust-Cost system, 14 junk Legendaries is 31.4% “ownership” of the Journey to Ungoro expansion. And that illustrates perfectly why using only Dust-Cost is a lousy method.
A person who had those cards would have not had much effective ownership of the expansion set because those cards were not relevant. They could build a few snowflake decks for fun, and that’s fine. But a lot of them are just unusable junk.
And mathematically all the commons & rares are only 15.6% of the set using this method. Even though those cards include many high-value meta staples that have been constantly in use for 2 years. Stuff like Firefly, Glacial Shards, Rockpools, Igneous, Tar Creepers, Phoenix, Roc, Stormwatcher, Golakkas, Devilsaur Eggs, Stonehill Defender, Flappy Bird, Tolvir, Servant of Kalimos, McCaw, Razormaw, Stalker, Arcanologist, Flame Geyser, Shimmering, Steam Surger, Lost in the Jungle, Hydrologist, Spikeridge Steed, Vinecleaver, Binding Heal, Radiant Elemental, Shellraiser, Crystalline Oracle, Free from Amber, Hallucination, Fireplume, Primalfin, Volcano, Lakkari, Sentry, & Direhorns.
Are all the Commons/Rares important? Certainly not. There’s junk in those tiers as well. So in ideal “Set Ownership Metric” would be something that weights cost against usefulness all the way up an down the rarity tiers.
But there is no simple mathematical value you can create for usefulness because it’s a variable that changes constantly. It’s unacceptable to simply shrug and say, “Well, I guess I’ll just use dust cost by itself” because doing that results in valuation that is provable nonsense. The best solution I’ve been able to find is to just use the Collectible Card Percentage. It’s not the best solution - which would factor cost and usefuless. But it’s better than the alternatives and I’ll keep using it until someone can demonstrate something that is better. Hasn’t happened yet.
Then for free you can get 80+ packs ever expansion which will (on average) give you…
All the Commons
All (or almost all) the Rares
16 Epics
4.5 Legendaries
2,000 or so dust for crafting
Is that not plenty of content for both creativity and freedom?