It comes from a bird and sounds inexpensive (5)
I believe the answer is:
cheep
'it comes from a bird' is the definition.
The definition suggests a singular noun which matches the answer.
'sounds inexpensive' is the wordplay.
'sounds' shows a homophone (sound like).
'inexpensive' becomes 'cheap' ('cheap' can be similar in meaning to 'inexpensive').
'cheap' is a homophone of 'CHEEP'.
'and' is the link.
Can you help me to learn more?
(Other definitions for cheep that I've seen before include "High-pitched sound" , "Young bird's cry" , "Cry of new-born chick" , "Bird noise" , "Weak cry of young bird" .)