help.js

const monthlyRateColumn = ({ showDuration, monthlyRate, duration }) => ({
  text: columnText('currency', monthlyRate),
  subText: showDuration && (
    <span>
      {bankItemContent.rate.monthly}{' '}
      <Text fontWeight={fontWeight.BOLD}>
        {contentWithParams(bankItemContent.rate.duration, { duration })}
      </Text>
    </span>
  ),
});

const effectiveInterestColumn = ({
  minEffectiveInterest,
  maxEffectiveInterest,
  eitherOrEffectiveInterest,
  specialOfferType,
}) => ({
  text: columnText('percentage', minEffectiveInterest),
  subText:
    isValidRate(maxEffectiveInterest) &&
    (eitherOrEffectiveInterest
      ? contentWithParams(bankItemContent.rate.either, {
        rate: maxEffectiveInterest,
      })
      : contentWithParams(bankItemContent.rate.effective, {
        rate: maxEffectiveInterest,
      })),
  highlighted: Boolean(specialOfferType),
});

const debitInterestColumn = ({
  minDebtInterestRate,
  maxDebtInterestRate,
  eitherOrEffectiveInterest,
}) => ({
  text: columnText('percentage', minDebtInterestRate),
  subText:
    isValidRate(maxDebtInterestRate) &&
    (eitherOrEffectiveInterest
      ? contentWithParams(bankItemContent.rate.either, {
        rate: maxDebtInterestRate,
      })
      : contentWithParams(bankItemContent.rate.effective, {
        rate: maxDebtInterestRate,
      })),
});

I would rather combine only the last two methods :)

const interestColumn = ({
  minInterestRate,
  maxInterestRate,
  eitherOrEffectiveInterest,
  specialOfferType = false,
}) => ({
  text: columnText('percentage', minInterestRate),
  subText:
  isValidRate(maxInterestRate) &&
  (eitherOrEffectiveInterest
    ? contentWithParams(bankItemContent.rate.either, {
      rate: maxInterestRate,
    })
    : contentWithParams(bankItemContent.rate.effective, {
      rate: maxInterestRate,
    })),
  highlighted: Boolean(specialOfferType),
});