Cheap deposit backed with very little money (8)

'cheap' is the definition.
Both the answer and definition are adjectives.
Perhaps there's an association between them I don't understand?

'deposit backed with very little money' is the wordplay.
'deposit' becomes 'put' (I've seen this in other clues).
'backed' says the letters should be written in reverse.
'with very little money' becomes 'penny' (I can't explain this - if you can you should give a lot more credence to this answer).
'put' in reverse letter order is 'tup'.
'tup'+'penny'='TUPPENNY'

Can you help me to learn more?