adjective

(of a price) much too high; exorbitant.

£2,700 for that guitar is extortionate

exorbitant,excessively high,excessive,sky-high,outrageous,preposterous,immoderate,unreasonable,inordinate,prohibitive,ruinous,punitive,inflated,more than one can afford,over the odds,criminal,steep,stiff,over the top,OTT