while there were a few different cards that required six mana (Personal Incarnation, Force of Nature, Demonic Hordes, Shivan Dragon, etc), Lord of the Pit was the only one that demanded seven

As it stands, the prices are as follows: Secret Lair x Monster Hunter: The Hunt Blind Obedience - around $3 Snap - around $2.50 Village Rites - around $0.25 Mizzium Mortars - around $0.45 Tooth and Nail - around $2 Total value: $8.20 Secret Lair x Monster Hunter: The Hunters Grand Abolisher - around $10 Archaeomancer - around $0.20 Grim Haruspex - around $1.30 Imperial Recruiter - around $12 Champion of Lambholt - around $2 Total value: $25.50 Secret Lair x Monster Hunter: The Monsters Nezahal, Primal Tide - around $8 Sarulf, Realm Eater - around $0.35 Vaevictis Asmadi, the Dire - around $1 Ziatora, the Incinerator - around $0.30 Drakuseth, Maw of Flames - around $0.50 Total value: $10.15 Secret Lair x Monster Hunter: The Monsters 2 Wasitora, Nekorus Queen - around $0.50 Kalamax, the Stormsire - around $0.40 Amareth, the Lustrous - around $0.25 Razaketh, the Foulblooded - around $8 Total value: $9.15 Sol Ring is generally inexpensive on its own (at about $1.20), and while it's a collector's item when it comes out in different, special versions, this doesn't really increase the value of the superdrops

This is card advantage already but you can get more spells later in the game after you've got the mana
Question #3 A player mana weaves their deck, then shuffles it well afterwards, believing that this helps them draw better cards