There are also cards like Overlord of the Hauntwoods which creates mana-producing lands from thin air, Defiler of Vigor which lets you pay life instead of green mana, and Domri, Anarch of Bolas which both adds mana and prevents your creatures from being countered
The double seven is flavorful, to be sure, but 777 wouldve gotten that across too
For roughly $2, its one of the best and most reliable counterspells you can play
How many lands or key pieces enter tapped
You can still play most of the format without spending an arm and a leg for one super expensive card
Enchantment Enchantment (CTRL to add secondary) Land Land (CTRL to add secondary) Planeswalker Wrenn and Realmbreaker Lands you control have ": Add one mana of any color." +1: Up to one target land you control becomes a 3/3 Elemental creature with vigilance, hexproof, and haste until your next turn