She's not talking about buying copious amounts of stuff, though. Or buying random things she doesn't need. Or dozens of disposable things. If someone chooses to spend a lot of money on a specific thing that they think is going to make their life easier - not just because it's the latest or because they want to show off about it or because it's new for the sake of it or because they get pleasure from the buying or because they think that owning it will make them happier - but because it will make something they do every day easier, why not? If they can afford it, something that makes their life easier might well make them happier.
I think that's very different from someone saying that it's the buying or the owning or whatever that makes them happy, or people who buy loads of things that never get used 'just because', or people who want something just for the name/status/newness but where it isn't actually any different from any old versions.
I don't think I could afford £300 for a hair dryer, I don't think it would make that much difference to my hair (though I'm intrigued by the idea, and if it would mean my hair stayed curly, but not frizzy, I might want to know more), and I think it's not something that I'd personally consider worth the money, but it doesn't seem like excessive consumerism for the sake of it. I spend £200 on an IPL machine to get rid of the hair on my face and body, when tweezers, threading, and razors did exactly the same job much more cheaply. But this is faster and easier. Definitely a luxury though, and I had to think about it and save for a while, but decided it was worth it. Yes, we are lucky that we can make some of these choices, and I think it's important not to lose sight of that, and to realise that they are luxuries. But you can have some at times without being a bad person.