I agree. Diptyque candles are beautiful. I have a biscuit one which is my absolute favourite. Bought specifically for Autumn evenings. Beautiful things you own should be used and not just for show. Life is too short. I feel the same way about expensive underwear. Don't keep it for best.
I think everyone's version of wanky is different. Like the gel nails mentioned, it really depends how well they are done. They can be well done and classy, or awful and cheap.
We have an Aga, shoot our own game, have our own fishing boat and also have hens and bees so therefore eat our own beautiful eggs and honey. I'm a food snob, so all my food is either organic and home grown, or from Waitrose / M&S. I make my own chutneys, jams, candles and artisan soaps and my family receive very poncy home made gifts at Christmas. I think that's more of a rural lifestyle, though than wanky per se. I was also on Masterchef back in the day where it was rather wanky / posh.
I also use expensive wicker hampers and vintage brown leather suitcases as 'props' / storage and have only Neom products in the bathroom. I think it depends what you prefer to spend your money on (I don't go out much, so never buy cocktails etc)
I use Fortnum's Royal Blend tea, and have a few of their biscuit tins. Nicking the idea of keeping cotton pads in the Fortnum's biscuit tins.