Anti-meta / Dragoon Subterror in the future
Condition of the card Mint/Near Mint : As good as new, often stored directly in sleeves
This card is luckily available in all conditions, and thus cheaper prices, so you should be able to pick it up regardless of your budget
For example, Elsha lets you continuously cast Sensei's Divining Top from your library with just one mana reducer in play
In Pioneer, with decks that are both resilient to interaction and can quickly go over the top like Lotus, Mono-Green, Convoke I see two key scarce resources: High impact one mana cards- Your list on which make the cut for high-impact will differ, but I think it is safe to say there are fewer than 10 in the entire format: Llanowar Elves, Elvish Mystic, Fatal Push, Thoughtseize, Consider and a few others