Turn up with £50 too much for a garment (8)
I believe the answer is:
pullover
'a garment' is the definition.
(pullover is a kind of garment)
'turn up' is the wordplay.
'turn' becomes 'pull' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'up' becomes 'over'.
'pull'+'over'='PULLOVER'
'with ps50 too much for' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for pullover that I've seen before include "Jersey" , "Go to side of road" , "Sweater or jumper" , "top gear?" , "Knitted garment" .)