To find the current market price of a Pokemon card, your best bet is to go to ebay and search sold listings (not "for sale" listings): Go to ebay
Six mana is a hefty price to pay for an enchantment that doesnt affect the board though
Gruul also plays around with effects like Borborygmos Enraged and Domri Rade that allow you to reveal cards before putting them in your hand, but Im leaving those effects aside
You can activate Tyvar's first ability even if Tyvar is already tapped
7 Dawnglade Regent The King Of Keep-Away Another pricey green creature, Dawnglade Regent is a monarch-based creature that can keep your entire board safe so long as you hold the crown
But, and here's where the design adds in some deck building, the Goblin Kaboomist's toughness is exactly 2, meaning if you can enhance his toughness in any way, he can survive his own mistakes