Infer `runtime_required` just once

        if resource_type not in VALID_RESOURCE_TYPES:

            raise ValueError(f"Invalid resource requirement type '{resource_type}'")

        self.resource_type = resource_type

        self._runtime_required: Optional[bool] = None

    @property

    def runtime_required(self):

        if self._runtime_required is None:

        try:

            float(self.value_or_expression)

                self._runtime_required = False

            self.runtime_required = False

        except ValueError:

                self._runtime_required = True

        return self._runtime_required

            self.runtime_required = True

    @staticmethod

    def from_dict(resource_dict):