Shadowless cards vary in value based on their condition and rarity, but theyre desirable for collectors because there arent very many in circulation
Value is driven as much by the Pokemon or item depicted as by technical rarity
Ultimately, it wont be worth doing so if your deck doesnt have some manner of sacrifice theme and ways to use the extra mana, but Magic has been incredibly long on both of those things for years now, and sacrifice decks show up in more and more Cubes all the time
Metamorphosis on a LV1 monster like a Magical Merchant for Thousand-Eyes Restrict can be a stronger play than it would be in Goat Control, because it not only can steal an opponents monster, but also provide you with the light and dark that you need later down the road
The best card to face a Lost Box is Klefki, which blocks Comfeys Flower Selecting and, therefore, blocks any early attempt to set a Lost Zone