In this context, the plaintiffs assert that, in the light of the difference in the refund amount, the purpose in disadvantaging the sale of beer in non-refillable bottles was to discriminate against the Bond brewing companies as interstate brewers in favour of the domestic brewers in South Australia. The defendant resists this conclusion for three reasons: first, that 15 cents is also fixed by reg. 7(b) as the refund amount for a non-refillable container for a low alcohol wine-based beverage; secondly, that the fixing of the refund amount at 15 cents advantaged C.U.B. as much as the domestic brewers so long as C.U.B. supplied beer in refillable bottles; and, thirdly, that the need to conserve energy resources requires or justifies more severe burdens on the sale of beer in non-refillable bottles. The first reason given by the defendant is not persuasive. If the refund amount fixed for non-refillable beer bottles far exceeded what was thought necessary to ensure the success of the scheme for the return and collection of containers, the relevant provision was not appropriate and adapted to that end; the fact that a like refund amount is fixed for non-refillable containers for low alcohol wine-based beverages cannot affect that conclusion. As for the second reason, the impact of the provision on C.U.B. might tend to suggest that the intended legislative object was not to discriminate against interstate brewers. However, it is not a conclusive consideration. It does not negate the purpose of discriminating against interstate trade consisting, in the main, of the trade of the Bond brewing companies (cf. Exxon Corporation v. Governor of Maryland [28] ). After all, it was the growing market share of those companies, not C.U.B., that threatened the market share of the domestic brewers. Discrimination in the relevant sense against interstate trade is inconsistent with s. 92, regardless of whether the discrimination is directed at, or sustained by, all, some or only one of the relevant interstate traders.