I have a lot of trouble characterizing tools as luxury goods. I don't consider my Dewalt tools "Luxury Goods" and they cost roughly twice what basic Harbor Freight tools cost.
You pay for longevity and performance. It's no different with phones/ tablets/ computers. If you want a phone or tablet that lasts 4+ years there is only one brand that offers that kind of device life.
Also, with Apple cranking out the base iPhone at $400, and the massive second hand market for iPhone, it's hard to argue many people associate the brand with luxury the way they do Coach or other luxury brands.
If anyone thought Apple was a "luxury" brand, the flop of the solid gold Apple Watch "Edition" sub-brand should have disabused them of the notion.