Payment arrangement cheaper? I rush, madly (4-8)
I believe the answer is:
hire-purchase
'payment arrangement' is the definition.
(type of purchase arrangement)
'cheaper? i rush madly' is the wordplay.
'madly' is an anagram indicator.
'cheaper'+'i'+'rush'='cheaperirush'
'cheaperirush' with letters rearranged gives 'HIRE-PURCHASE'.
(Other definitions for hire-purchase that I've seen before include "Way of buying expensive items" , "Never-never" , "Payment by instalments" , "Easy terms" , "Instalment plan" .)