Paltry sum socialist said was mailed (3,4)
I believe the answer is:
red cent
'paltry sum' is the definition.
(red cent can mean a tiny amount of money)
'socialist said was mailed' is the wordplay.
I cannot really see how this works, but
'socialist' could be 'red' (socialism is often associated with the colour red) and 'red' is located in the answer.
'said' could be 't' (I've seen this in other clues) and 't' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for red cent that I've seen is " coin".)