For example, at Portland Regionals, it was common for players to play copies of Reset Stamp
If you're committed to buying all four, complete sets are available, but they'll cost at least $770
The price for an HP lotus had dropped down to around $6,000 on TCGPlayer at the time, so I started looking a stores with HP lotuses for sale, and what their buylists were, so I could try and cover at least 60% of the cost with trade in
Basically any card that says when you perform your deck's dedicated action, draw a card is solid since it adds card advantage in addition to whatever you were doing
You can tap it with two mana to sac a token for a card to make them all Clues, or three mana to pay a life for making a free 1/1 Fish token or four mana to make Treasures for ramping
Its the same account that you need if you enter an official tournament for the physical card game, so you may have already signed up