'A list of dicts of all the currencies and prices for this tier.
:param int provider: A provider, using the PAYMENT_* constant.
If not provided it will use settings.PAYMENT_PROVIDERS,'

def prices(self, provider=None):

    providers = ([provider] if provider else default_providers())
    return [model_to_dict(o) for o in self.pricecurrency_set.filter(provider__in=providers)]
