While you could use any energy type to fullfil these requirements, a Double Colorless Energy would provide two energy in a single turn
But the modifications mechanic is much better to keep up since the new reconfigure equipment means you wont be lacking creatures forever
Also, once the ability is on the stack, even if the creature with the mechanic is removed from the battlefield or combat one way or another, the smaller creature will still get the +1/+1 counter as long as its power is still less than the Mentor creatures was as it last existed in combat
Its a subtle but powerful enhancement piece, turning routine plays into larger swings as your board expands throughout the game
Everything depends on the mentality, though, and if the perception is of rarity, itll be priced that way
Dinosaur typal has a simple but effective playstyle that can be almost comforting at times