They have their own rarity
If you like Limited at all and draft or play Sealed, then the value of those draft boosters (and the draft booster boxes) goes up

Water Energy Color : Blue Associated with : Water-type Pokemon Common effects : Healing, defensive abilities Weakness/Resistance : Usually weak to Electric, resists Fire Grass Energy Color : Green Associated with : Grass-type Pokemon Common effects : Healing, energy acceleration, poison Weakness/Resistance : Usually weak to Fire, resists Water Electric Energy Color : Yellow Associated with : Electric-type Pokemon Common effects : Paralysis, energy acceleration Weakness/Resistance : Usually weak to Fighting, resists Metal Psychic Energy Color : Purple/Pink Associated with : Psychic-type Pokemon Common effects : Confusion, card manipulation Weakness/Resistance : Usually weak to Dark, resists Fighting Fighting Energy Color : Orange/Brown Associated with : Fighting-type Pokemon Common effects : High damage, simple effects Weakness/Resistance : Usually weak to Psychic, resists Dark Dark Energy Color : Black/Dark Purple Associated with : Dark-type Pokemon Common effects : Disruption, damage manipulation Weakness/Resistance : Usually weak to Fighting, resists Psychic Metal Energy Color : Silver/Gray Associated with : Metal-type Pokemon Common effects : Damage reduction, energy efficiency Weakness/Resistance : Usually weak to Fire, resists Grass Fairy Energy Color : Pink/Light Purple Associated with : Fairy-type Pokemon Common effects : Healing, anti-Dragon effects Weakness/Resistance : Usually weak to Metal, resists Dragon Dragon Energy Color : Gold/Orange gradient Associated with : Dragon-type Pokemon Common effects : Requires multiple energy types Weakness/Resistance : Usually weak to Fairy, no resistance Colorless Energy - The Universal Power Colorless Energy is the Swiss Army knife of the Pokemon world

As a Fire/Flying type Pokemon from Generation I,Charizard has appeared in numerous Pokemon Trading Card Game sets since its introduction
While other frogs can trigger this ability, you can get plenty of additional value if Grolnok is the only frog you have around
Given its postal distribution history, even a raw ungraded copy in decent shape commands a massive price tag of $4,000 to $5,500, making it just as expensive as some PSA 10 cards on this list