Spore Frog is an excellent cheap creature that will both protect you and build up a graveyard
For an example of what Topps 1951 cards looked like, take a look below: For that series only, it was framed to be more like a game (a trading card game, perhaps?) , and each players cards could affect the game, such as drawing a strike or a ball card would mean your pitcher threw a strike or a ball, etc
You can only activate 1 "Cyber Energy Shock" per turn
(Big Furry Monster) is a silver-bordered card, and Marit Lage is a token, so they don't count and you know it
There are 3 more monsters that become Umi and mention Atlantis (plus the Advent of Atlantis Continuous Spell Card), so youll have plenty of Umi to flood the field
Mostly, it is for collectibility reasons that certain Magic: The Gathering cards can become so expensive