One comic off-beat, a learner becoming cheap (10)
I believe the answer is:
economical
'cheap' is the definition.
(I've seen this before)
'one comic off-beat a learner' is the wordplay.
'off beat' indicates anagramming the letters.
'learner' becomes 'l'.
'one'+'comic'='onecomic'
'onecomic' is an anagram of 'economic'.
'economic'+'a'+'l'='ECONOMICAL'
'becoming' acts as a link.
(Other definitions for economical that I've seen before include "Inexpensive" , "saving money" , "Using little" , "Providing good value" , "Money-saving" .)