It allows you to untap and play even more spells
Again, it's probably easiest to evaluate these "while at a location" abilities as if they just add 1 ink to the cost of the character, as it will usually cost you that much to move them there
If you cant afford the pricier cards like Sword of Fire and Ice, Zephyr Boots is a decent enough option, particularly as it grants evasion
Lets apply this concept to a specific example, the Stone Tongue Basilisk deck: 1-cost cards: Llanowar Elves, Fog, Rangers Guile, Giant Growth 2-cost cards: Rampant Growth, Mulch, Grisly Salvage 5+ cost cards: Natures Revolt (costs 5), Stone-Tongue Basilisk (costs 7) In this example, the distribution would be 16 cards with a mana value of 1, 12 cards with a mana value of 2, and 8 cards with a mana value of 5 or higher