rare blastoise pokemon card PSA 10]{202/165}BLASTOISE ex favorite character Top 10 Most Valuable Blastoise

Theres a lot of established heuristics on this subject, and a few points I can toss in to help you construct an optimal mana base for Standard, Modern, Pioneer, or whatever MTG format you prefer

So no, you cant just cheese the rules and wait until you roll an 8 to pay the mana

However, certain cards had abilities that let you cast them as instants before this, beginning with [c]King Cheetah[/c], in Visions

If you are a "kitchen table" player with a group of friends, try buying a complete playset of commons/uncommons for each set that comes out (4x of each card.) This will typically run around $20-30 on ebay and yet greatly expand your collection