Like most Magic: The Gathering cards, the value of Sunken Ruins depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Double Masters)
At the time, these Creature types were largely created for flavor purposes
Theres one thing you can change though, your Commander between games, for example you can play with Aragorn, King of Gondor for Game 1 and with Satya, Aetherflux Genius for Game 2, although you need to have him in the 99 cards presented in Game 1
It doesnt work as seamlessly as it would in real life, but having the option to search the cards according to their name helps a lot
in decks like Zada, Hedron Grinder, not only are you attacking with a wide board of creatures, but you also want to cast and copy cantrips to draw massive amounts of cards, which Surge can do
Reducing the cost of colored spells permanently is very strong, especially in combo decks