27 cards where (the set is “uds” or the set is “ulg” or the set is “usg”) and the USD price > 15

Academy Rector (Urza's Destiny #1)
Argothian Enchantress (Urza's Saga #234)
Back to Basics (Urza's Saga #62)
Deranged Hermit (Urza's Legacy #101)
Exploration (Urza's Saga #250)
Gaea's Cradle (Urza's Saga #321)
Gilded Drake (Urza's Saga #76)
Goblin Lackey (Urza's Saga #190)
Goblin Welder (Urza's Legacy #80)
Great Whale (Urza's Saga #77)
Grim Monolith (Urza's Legacy #126)
Karn, Silver Golem (Urza's Saga #298)
Lifeline (Urza's Saga #299)
Memory Jar (Urza's Legacy #129)
Metalworker (Urza's Destiny #135)
Palinchron (Urza's Legacy #38)
Phyrexian Tower (Urza's Saga #322)
Replenish (Urza's Destiny #15)
Rofellos, Llanowar Emissary (Urza's Destiny #118)
Serra's Sanctum (Urza's Saga #325)
Show and Tell (Urza's Saga #96)
Time Spiral (Urza's Saga #103)
Tolarian Academy (Urza's Saga #330)
Treachery (Urza's Destiny #50)
Urza's Incubator (Urza's Destiny #142)
Yavimaya Hollow (Urza's Destiny #143)
Yawgmoth's Will (Urza's Saga #171)

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