The 49 obviously can't come out of nowhere and it surely is not because of some attribute. It seems like you are editing the file based on wrong documentation. Which column are you editing for mana cost?
Counting from 0 or 1?If you're counting from 0, either the documentation is completely wrong -- which should not be the case -- or you're doing something wrong / looking at the wrong spell or something.
uint32 powerType; // 41 m_powerTypeuint32 manaCost; // 42 m_manaCostuint32 manaCostPerlevel; // 43 m_manaCostPerLevel
uint32 ManaCostPercentage; // 204 m_manaCostPct
int32 EquippedItemClass; // 68 m_equippedItemClass (value)int32 EquippedItemSubClassMask; // 69 m_equippedItemSubclass (mask)
uint32 Targets; // 16 m_targets
SPELL_ATTR0_REQ_AMMO = 0x00000002, // 1 on next ranged SPELL_ATTR0_ABILITY = 0x00000010, // 4 client puts 'ability' instead of 'spell' in game strings for these SPELL_ATTR0_NOT_SHAPESHIFT = 0x00010000, // 16 Not while shapeshifted SPELL_ATTR0_IMPOSSIBLE_DODGE_PARRY_BLOCK = 0x00200000, // 21 Cannot be dodged/parried/blocked
SPELL_ATTR1_DISMISS_PET = 0x00000001, // 0 for spells without this flag client doesn't allow to summon pet if SPELL_ATTR1_CANT_BE_REDIRECTED = 0x00000008, // 3 SPELL_ATTR1_UNK4 = 0x00000010, // 4 stealth and whirlwind SPELL_ATTR1_MELEE_COMBAT_START = 0x00000200, // 9 player starts melee combat after this spell is cast
SPELL_ATTR3_DEATH_PERSISTENT = 0x00100000, // 20 Death persistent spells
SPELL_ATTR4_TRIGGER_ACTIVATE = 0x00000200, // 9 initially disabled / trigger activate from event (Execute, Riposte SPELL_ATTR4_USABLE_IN_ARENA = 0x00020000, // 17
SPELL_ATTR5_SINGLE_TARGET_SPELL = 0x00000020, // 5 Only one target can be apply at a time