mtg draw card when creature enters the battlefield Guardian Project (RVR) #349 Rumor Gatherer

Speaking of your collection, the best place in North America to find new cards is at Danireon

Well of Lost Dreams excels in that aspect: A colorless card that probably fits black or white decks

Urtet, Remnant of Memnarch Urtet, Remnant of Memnarch cares about the Myr

Current Price: $30-35 Future Price (12-18 months): $50+ Sliver Queen was actually one of the earliest EDH based spikes for the Reserved List, initially popping from $30 to $45 in the summer of 2013

Helm of the Host A fan favorite, but a citizen of Clunk City nonetheless

All other lands in Antiquities got at least two different printings at different rarities