Like some churches, requiring expensive form of light (8)
I believe the answer is:
steepled
'like some churches' is the definition.
(I've seen this before)
'expensive form of light' is the wordplay.
'expensive' becomes 'steep' (I've seen this in another clue).
'form of light' becomes 'LED' (light-emitting diode).
'steep'+'led'='STEEPLED'
'requiring' is the link.
(Other definitions for steepled that I've seen before include "like some churches" , "sort of building Fred liked?" , "characteristic of some churches?" .)