Many electronics and appliances shops in Australia make sure to offer a wide range of electronics for the consumers. They have a wide range of things available for online and local buyers so that the customer will not have to explore the whole market if they have to buy multiple things, rather they find via one seller or the store.
But the fact is that when you are buying things from different categories, and brands it is not possible to get the same quality across all brands for all kinds of products. You might have to consider analyzing the quality and the suitability per products without generalizing the same rule at all.
As for example, if you are looking to buy multiple things like headphones, 4k TV, a smart watch or TVs along with other things including projector accessories, home security systems etc. you can find them online on any store offering home appliances or electronics in different categories. But to analyze each product, make sure to compare and choose to depend on the features, benefits and the reviews the products have obtained.
So whether you buy an Xperia or are looking for a TV, you don't have to generalize the brand quality of one product over others as each brand has the different set of specialties and look for the best things that suit your need, are genuinely helpful and offer features you need.
Further, you must compare things for the competitive pricing. Sometimes if you are buying the things of the same brand from one seller you may compare it with other seller offers to know if you could get some discount.