Where you'd expect to find lots of change, as American buck fights in Ring (9)

'where you'd expect to find lots' is the definition.
The definition suggests a singular noun but the answer is a plural noun.

'change as american buck fights in ring' is the wordplay.
I cannot really see how this works, but
'change' could be 'cash' (cashing is a kind of changing) and 'cash' is located in the answer.
'fights' could be 'boxes' and 'boxes' is found within the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).

'of' acts as a link.

Can you help me to learn more?