I'd use variables to remove duplication (and thus repeated DOM selection):

```coffeescript
is_paying_fees_selector = $('#pay_payment_fees')
return unless is_paying_fees_selector

paying_fees_placeholder = $('[data-pay-payment-fee]')
value                   =  is_paying_fees_selector.is(':checked') ? '1' : '0'
paying_fees_placeholder.val(value)
```