Watch that wife gets cheap (3)
I believe the answer is:
low
'cheap' is the definition.
(thesaurus)
'watch that wife' is the wordplay.
'watch' becomes 'lo' (archaic exclamation meaning 'look!').
'that wife' becomes 'w' (abbreviation).
'lo'+'w'='LOW'
'gets' is the link.
(Other definitions for low that I've seen before include "Deep; moo" , "Depressed; moo" , "Deep sound made by cattle" , "Inferior, cow's call" , "Not high - that's mean" .)