Four mana is still a lot, however
Track where pricing, margin distribution or market positioning are out of line with competitors, exchanges or expected performance patterns before sharp money finds the gap
Prices on desirable Enchanted cards spike at launch hype, dip slightly 3 to 6 weeks post-launch as market supply stabilizes, then trend back upward as pack supply dries up
Some, like Candelabra of Tawnos, The Abyss and Eureka, are already extremely expensive and probably not worth buying unless you really, really want to play High Tide
Bramble Sovereign Bramble Sovereign is a great bargaining chip with open mana
Booster packs for Disney Lorcana: Shimmering Skies include a mostly random assortment of cards, with rarity determining some elements of distribution