Plateau (Mountain Plains) $8 steady
Scrubland (Plains Swamp) $8 to $15 to $10
Badlands (Swamp Mountain) $7 to $15
Taiga (Mountain Forest) $9 to $15
Savannah (Forest Plains) $15 to $25 to $15
Tropical Island (Forest Island) $15 to $30
Bayou (Swamp Forest) $12 to $41
Underground Sea (Island Swamp) $17 to $42
Volcanic Island (Island Mountain) $7 to $48
Tundra (Plains Island) $10 to $60
Strip Mine ($2 to $12)
Tolarian Academy ($7 to $20 to $10)
Bazaar of Baghdad ($5 to $18)
June 21 update: all of these cards have gone down in price a lot, but at some point I expect them to stabilize and begin to climb up in value.
June 28 update.