Go into a price change that's an eye-opener (6)
I believe the answer is:
pierce
'go into' is the definition.
(piercing is a kind of going into)
'a price change that's an eye-opener' is the wordplay.
'change' indicates an anagram.
'that's' says to put letters next to each other.
'opener' says to take the initial letters.
The initial letter of 'eye' is 'e'.
'price' is an anagram of 'pierc'.
'pierc'+'e'='PIERCE'
(Other definitions for pierce that I've seen before include "Make hole in with something sharp" , "Perforate" , "Penetrate with sharp point" , "Make hole in with sharp object" , "Stab" .)