exorbitant
1. [ adjective ] greatly exceeding bounds of reason or moderation
Synonyms: outrageous steep unconscionable usurious extortionate
Examples:

"exorbitant rent" "extortionate prices" "spends an outrageous amount on entertainment" "usorious interest rate" "unconscionable spending"

Related terms: immoderate
Similar spelling:   exorbitantly
  exorbitance
  exurbia