While you will generally want to cast combat-oriented sorceries or enchantments during your first main phase (like Blanchwood Armor), for the most part you will want to wait to cast other spells and creatures until after combat occurs
While this can be frustrating for those who live near the store, there are several options you can head to if you want to sell your used cards
Reputable operators display jurisdictional credentials, verification badges, and accessible policy pages
I have entire first edition sets WoTC sets, mostly ungraded, but very few of singles seem to break that point
Regional Exclusives: Cards released in specific regions, such as Japanese alternate-art planeswalkers
This card deserves its flowers as the best Fairy-type card ever and one of the most expensive cards from the Sun & Moon era