How to Know Which Set Your Card Belongs In For cards after 1998: Most sets released after Exodus (June 15, 1998) have the set code printed at the bottom left corner of the card, making it easy to recognize which set your card belongs to
You could offer $500, but since you are actually trying to negotiate and not just throwing out a hail mary, an offer this low could make the seller less interested in negotiating
Spike functions the same way
P/T Number 349 Language English Legal Formats Commander, Legacy, Modern, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Pauper, Pioneer, Standard, Timeless Rulings (3/19/2021) The ability that defines Tarmogoyf's power and toughness works in all zones, not just the battlefield
Too Much of a Good Thing
Plus, keeping one mana up as a Blue player is a completely natural thing to do, and just the threat of this card will have your opponents reconsidering their life choices