My goal is not to fault you for playing those cards - I just feel the broader EDH format as a whole is becoming quite solved, in part by people turning to net-decking or using automatic online suggestion tools too often
Those three cards are Fated Firepower ($10), Appa, Steadfast Guardian ($8), and Redirect Lightning ($8, the only rare in the top 10)
It is sometimes better to hold off on ramping early in the game so you can use ramp spells later once you have multiple permanents with landfall abilities to trigger them multiple times in one turn
The more foes the stronger this is and they encourage each other to attack them
one is randomly found in each Prerelease Pack
This common card now goes for a fair bit of money thanks to its prolific use in the old Channel Fireball decks, back when the game had just 40 card decks and no real restrictions on other very powerful cards (looking at you Black Lotus)