Urza's Filter 
Artifact
$4.88 #14664 0.30 26.0 years
Multicolored spells cost 
less to cast.
less to cast.Click a line or tag to filter
Cards similar to Urza's Filter expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
Helm of Awakening84%
$1.61↓#1927↑0.3229.7 years↑
"Spells cost 
less to cast."
less to cast."
Stone Calendar80%
$14.91↑#20542↓0.3732.2 years↑
"Spells you cast cost less to cast."
less to cast."
Seal of the Guildpact76%
$0.36↓#125370.14↓10.9 years↓
"Each spell you cast costs less to cast for each of the chosen colors it is."
less to cast for each of the chosen colors it is."
Memory Crystal76%
$2.23↓#24089↓0.19↓28.3 years↑
"Buyback costs cost less."
less."
Herald of Kozilek74%
$0.36↓#6409↑0.2911.0 years↓
"Colorless spells you cast cost less to cast."
less to cast."
Pearl Medallion74%
$7.43↑#429↑0.19↓29.0 years↑
"White spells you cast cost less to cast."
less to cast."
Sapphire Medallion72%
$7.87↑#354↑0.3429.0 years↑
"Blue spells you cast cost less to cast."
less to cast."
Ruby Medallion72%
$14.07↑#293↑0.2829.0 years↑
"Red spells you cast cost less to cast."
less to cast."
Uthros Psionicist71%
$0.22↓#9584↑0.221.2 years↓
"The second spell you cast each turn costs less to cast."
less to cast."
Raging Battle Mouse71%
$0.22↓#124270.00↓3.1 years↓
"The second spell you cast each turn costs less to cast."
less to cast."
Naiad of Hidden Coves70%
$0.22↓#10618↑0.06↓6.7 years↓
"During turns other than yours, spells you cast cost less to cast."
less to cast."
Highspire Bell-Ringer70%
$0.16↓#10943↑0.00↓1.5 years↓
"The second spell you cast each turn costs less to cast."
less to cast."
Thornscape Familiar70%
$0.32↓#18091↓0.10↓25.7 years
"Red spells and white spells you cast cost less to cast."
less to cast."
Geyser Drake70%
$0.13↓#8697↑0.19↓2.5 years↓
"During turns other than yours, spells you cast cost less to cast."
less to cast."
Emerald Medallion70%
$5.16↑#582↑0.3029.0 years↑
"Green spells you cast cost less to cast."
less to cast."
Jet Medallion70%
$13.42↑#274↑0.2729.0 years↑
"Black spells you cast cost less to cast."
less to cast."