Chance of a thousand in income, but not five (10)

'chance' is the definition.
(thesaurus)

'a thousand in income but not five' is the wordplay.
'a thousand' becomes 'k' ('K' can be a synonym of 'thousand').
'in' means one lot of letters goes inside another.
'income' becomes 'livelihood' (someone's job or source of money).
'but not' suggests deleting specific letters.
'five' becomes 'v' (roman numeral).
'livelihood' with 'v' removed is 'lielihood'.
'k' inserted within 'lielihood' is 'LIKELIHOOD'.

'of' is the link.